Separating the Gybe from the Turn

Separating the Gybe from the Turn

Something I’ve found to help students when they’re learning to gybe is to separate the gybe from the act of turning the boat. A gybe can require no turning at all, and understanding this will improve your gybes and reduce your likelihood of capsizing.

Most of the time, the reason we are gybing is because we want to turn and go the other way while sailing downwind. Maybe we've reached Ashby Ave and we have to head back before we start to feel the disapproving glare of the day leader through their binoculars. Or we're doing tight circles around a buoy and have to keep turning through the gybe. But really, gybing has nothing to do with turning, other than if we're turning downwind, we have to eventually gybe or we just can't continue the turn.

The gybe itself is nothing more than changing tacks (from port to starboard or vice versa) while sailing downwind. Or to put it more simply: a gybe is flipping the sail from one side of the boat to the other. If you’re on a dead downwind run, there is no turning needed. In fact, there are reasons to gybe that don't involve a turn at all. A common case is during racing--if you're on a dead run and want to obtain right of way by switching from port to starboard tack. No turning needed. Or maybe you're headed back home and the wind shifts a bit and you realize you're now sailing by the lee, so you flip the sail to get yourself out of accidental gybe territory. No turning needed.

I've noticed a lot of students (understandably) connect the turn and the gybe and want to turn through the gybe, from broad reach to broad reach, which can often result in a capsize. To help disconnect the two actions I've started doing this exercise:

  • Get on a dead run. Get the jib to cross to the center of the boat and try to keep it there. Watch out for the accidental gybe, and tell your crew to do the same. If you have crew you may want to have someone hold the boom in place to avoid a gybe before you're ready.  They'll also be able to feel the main starting to get back-winded, so they can let you know you've turned too far off the wind.  Maintaining a dead-run can in-itself be tricky, and if you can hold this reasonably well in waves, you're off to a good start!
  • Look at what you're heading towards on the horizon. Try to find a fixed reference point.
  • Now gybe. Try to keep the boat headed dead downwind. Use your reference point on the horizon if it helps. Once the wind catches the sail on the other side, it will try to turn the boat up, so maintaining your heading will require some counter steer with the tiller.  Think of it as a light version of the S-turn.
  • Once you're confident you're still on a run, gybe again.
  • Now do it faster, back and forth, while maintaining course.
  • Try to get down to a few seconds between gybes.
  • By now you're probably at the rocks, so better tack your way back up to the restaurant and do some more.

I've found this tends to create a light bulb moment and hopefully makes gybing in general a little smoother.

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Michael Sherrell
I don't think I'd encourage correlating wind direction with landmarks. One of the most widespread problems at the club is sailing ... Read More
Saturday, 02 July 2016 07:53
Ryan Alder
Yea I'm on the fence about that part for that reason, and I don't always mention it, depending on how the student is doing. This i... Read More
Sunday, 03 July 2016 23:53
John Bongiovanni
On a dead run, you have some pretty good indicators on the boat. Ryan mentioned one in a way I hadn't thought of - the jib, and tr... Read More
Wednesday, 06 July 2016 22:50
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Slow Sailing

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Slow sailing is a Junior skill and an important one. The objective of slow sailing is to get to a fixed point in space (a dock, a man-overboard,
a buoy) with zero speed. The idea is to come in on a close reach course, where you have an accelerator and a brake.
With the mainsheet all the way out, the sail is depowered, and the brake is the wind and sea against the boat. Pulling in the mainsheet on the falls is the accelerator. You line yourself up on a close reach
course and sail to the target.

There are two skills involved:

1) lining yourself up on a close reach course to the target, and

2) slow sailing on that course to it.

Let's talk about hitting a buoy at zero speed, as it's the hardest of the maneuvers. When you dock, you usually have some room for error, as you don't have to get to a precise point on the dock. But wait, what about a busy Saturday where you have to thread the needle between the only two boats where there's any space between them to dock? If you can lightly touch a buoy on a slow-sail, you can do precision docking.

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Ryan Alder
I think 'maintain forward momentum' is the big one (once you get the concept of finding the right angle to the wind). I know I ha... Read More
Thursday, 23 June 2016 11:16
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Treasure Island Cruise

Treasure Island Cruise

On Tuesday April 19th, Mike and Nathan took Monica and me on a short cruise to Treasure Island. Why only two people? There were more spots on the boats!

It was a perfect day for sailing: the sun was out and a constant breeze blew gently. When I arrived at the club, Nathan and Monica were already getting the boats ready. I quickly changed into a "highly recommended wetsuit"(Did this mean we were aiming at getting wet?), choosing a sleeveless one because the beautiful conditions made me feel fearless.. I helped out as I could. I am new to the club, and what I like about CSC is that you are expected to quickly learn how to be independent on the water. It's both scary and fun— but today I was being fearless, after all.

Mike arrived and we got going pretty quickly. After a smooth beginning (ideal for nice conversations) the wind intensified a little bit and Nathan and I even rose the spinnaker! I was excited to get on the trapeze, something I remembered doing when I was younger. We arrived at Clipper Cove after noon; perfect timing for our picnic lunch. We took the time to enjoy the delicious chocolate brought by Monica and climbed on top of  the Yerba Buena Island to get a nice view of San Francisco.

The way back brought even more fun with swift wind in our back! I stayed on the trapeze almost all the way to the club, getting half soaked indeed but feeling invigorated. Mike and Monica had some trouble with their spinnaker, but enjoyed a nice speed anyway.

Having to put away the boats was only half-sad. You know why? Because I know I'll be going on another CSC cruise soon! 

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Sailing Small Circles

Sailing Small Circles
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Small Circles

This is one of the most difficult Junior skills, and it's quite important. But why is it important? In real life, how many  small circles are you going to do? Probably none, after you pass the Junior Test. But you probably will need to do fast turns upwind or downwind, and do fast tacks and gybes, possibly to avoid disaster (like hitting something). And maybe with newbie crew. Think about approaching the dock on a big south wind and getting turned in the wrong direction (like into the sea wall). That's what this maneuver is about. You may never do another full circle in your life, but you may need one or more of the maneuver's components.

The maneuver is also a stress test of your sailing skills. You have to do a bunch of things quickly and competently without time to think - they have to be instinctive. It's also a stress test of your crew communications skills for the same reason.

A real circle?

First of all, it's not really a circle. We think of it as looking like this, here counter-clockwise around a buoy:

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Michael Sherrell
John, do the instructions vary by wind speed? What wind speed are these instructions optimal for?
Thursday, 07 April 2016 06:50
John Bongiovanni
I think in any wind speeds where small circles make sense (that is, approaching 10 knots and more). In talking to people, the one... Read More
Thursday, 07 April 2016 17:35
Michael Sherrell
No, I think this is great. Actually made me rethink my own technique, such as it is, for which, thanks!
Thursday, 07 April 2016 20:23
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How to Make the Most of your Weight in High Winds

How to Make the Most of your Weight in High Winds
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During the summer months or during the addiction-satisfying winter storm sailing, you can often find yourself overpowered. I’ve also heard of this several times during senior tests where the tester “falls” overboard for the legendary single-handed man overboard, occasionally where the tester is “unconscious”, typically in something like 20 kts. As the wind comes up from a comfortable 10 kts, the full sailed Bahia and JY will begin to require a bit more leverage than hiking out supplies, depending on crew weight. This is the beginning of the wind range that requires, or at least benefits from, using the trapeze. If you’re comfortable with your crew and/or your ability to drive the boat, start to use this. It’s a lot of fun to trapeze while single-handing and is arguably the most fun you can have without flying the kite, but be prepared to swim on your first few outings.

As the wind increases further to the over 15 kt range, the challenge really starts to kick in. Depending on your and your crews weight and skill, you'll need to consider various ways to depower, the most obvious being reefing. If you're luffing your sail more than not, you should be reefed. Another way to depower your main sail, is to pull on your cunningham. As the wind comes up, you should also use your vang/gnav to flatten the sail and change the placement of your draft in balance with your additional cunningham. This is the standard sail trim and depowering technique. As you struggle to keep the boat powered and moving, you can start to ease your jib a bit. This has the tendency to twist off the top of the sail and allow the boat to breathe a little bit by opening the slot between your main and jib. Closing this slot is what causes the “speed bubble” in the main, due to the wind coming off the jib backwinding and the main. As you’re “more” overpowered, you can ease your vang/gnav to twist off the top of your main sail.

One of the things that I haven’t seen done often at CSC is changing the placement of the centerboard while sailing. It’s commonly thought, at least at first that your boat is “under control” if it’s upright, but in reality, your boat is only under control when you are able to make headway and able to maneuver in some capacity. For this reason, I suggest that when extremely overpowered (repeatedly capsizing or completely luffing), you try raising your centerboard a bit. If you look at the diagram, you can see that as the length of the centerboard is reduced, you allow the boat to slip sideways more, but at the same time, you’re reducing the rotational torque that it’s causing on the boat by reducing both its lever arm and area. This allows the boat to slip sideways more but also reduces the leverage and reduces the heeling “force.” Although you may immediately argue that this is hurtful to your ability to get upwind, it allows you to trim your sails as opposed to luffing. When your sails are luffing, the only force on them is to leeward. However, once your sails are trimmed and have some proper shape, you have a driving force forward. For this reason, it is best to trim your sails to your course, then trim your weight and centerboard to match each other in their torque (rolling force) on the boat. As the boat increases in speed, your centerboard will create lift, which will “lift” you to windward. This lift is proportional to your speed, so as your boat speed increases, your leeway will reduce dramatically. This is much preferred over the scenario where the overpowered boat drifts sideways and you can’t sheet the sails without risk of immediate capsize. 

In other words, if we focus on the rotation portion, the torque counteracting the wind and water comes from the crew weight (or the lead at the bottom of the keel in a keelboat). Torque is force multiplied by length, so getting your weight out of the boat more, such as being on the trapeze or hiking, benefits your righting moment dramatically. This is part of the reason sails are lowered when it’s windy, it reduces the heeling force (torque) on the boat. Likewise, you can do this by lifting your centerboard to “reef” your centerboard. This, like a reefing a sail, both reduces the area as well as the length over which this force is acting.

Another important thing that isn’t often mentioned around the club is the region around a beam reach that opens up in (very) high winds, which is affectionately called the zone of death (ZOD). The ZOD arises when it’s too windy to keep the boat upright with all your weight utilized to its limit on a reach. This is basically when you find yourself completely overpowered. In any case, the existence of the ZOD means that you are now limited to only upwind and downwind sailing and not too much in between. This is a result of a beam reach being your fastest and most powered up point of sail. When you’re sailing in winds with the ZOD, your next biggest concern, other than staying upright when sailing in a straight line, is getting between up- and downwind courses. To do this, you must make a smooth and decisive maneuver to bear away. It’s helpful to have your weight toward the back of the boat and have pre-eased the jib. Once downwind on a broad reach, you can relax a bit and steer for heel with the main eased a few feet off the aft quarter and ease in the gusts. The most important thing when sailing in these conditions is to keep the boat moving and flat. Once you have leeward heel, you will likely round up and broach, leading to your next chance to master the bear away. 

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Michael Sherrell
1. So running downwind in high wind conditions, you're saying to keep the main close to the centerline of the boat, just eased a f... Read More
Thursday, 17 March 2016 07:32
James Clarkson
1. In high wind conditions, what you really want is control over the boat and the best way to do this is with speed. The more spe... Read More
Thursday, 17 March 2016 10:23
Michael Sherrell
On all our dinghys except the Laser, you don't raise the centerboard, you swivel it. A little bit of it disappears into the hull, ... Read More
Sunday, 22 May 2016 20:32
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Demystifying Apparent Wind - Part 3

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The last in the series - Apparent Wind downwind.

It's hard to steer downwind. The waves toss the boat around more, and if you get tossed too much, you'll gybe when you don't want to. You can capsize on a broad reach in heavy winds and seas.

The biggest thing you have to deal with is apparent wind. On a downwind course, small changes in course, wind speed, and wind direction produce large changes in apparent wind.

We'll use the same 5 kt. true wind we've used before and the same Bahia-like boat. You're almost dead downwind - just 5 degrees short of it. Here's what it looks like:

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Demystifying Apparent Wind - Part 2

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Last time, we looked at apparent wind and how it changes as you change point of sail. In that discussion, the speed and direction of the true wind was the same and the boat direction changed. Here we look at what happens when you're keeping the boat course the same, the wind direction doesn't change, but the wind speed does. It increases (a puff) or it decreases (a lull). You get both of these as you're traversing the Novice Area on a normal day (westerly winds), as the trees and gaps between them on the breakwater to the restaurant cause this uneven wind.

Again, we're using our Bahia-like dinghy and a 5 kt. wind. You're sailing close-hauled, so it looks like this:

The boat is 45 degrees to the true wind, but only 30 degrees to the apparent wind. Normal. Then you get a puff, say a pretty big one (10 knots, double the speed but out of the same direction). In that instant, your boat speed doesn't change (it needs time to do that), but your apparent wind does. It looks like this:

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Michael Sherrell
The point being that when you get a puff you can head up and sail closer to the true wind, i.e., get upwind faster, rather than si... Read More
Monday, 22 February 2016 10:35
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Demystifying Apparent Wind - Part 1

Demystifying Apparent Wind - Part 1
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A very common problem my students have voiced is that they have trouble figuring out where the wind's coming from. On the one hand, it shouldn't be so hard - turn your head and feel the wind on your ears. When it's the same on both ears, you're either looking straight into the wind or straight away from it. Or (less accurate) look at the yarn on the side stay.

Yet it's not so simple. You think of the wind as coming from the same direction, but when you sail, it doesn't seem to do that. It seems to shift a lot. And "you told me we couldn't sail higher than about 45 degrees into the wind, but that yarn on the stay has a much smaller angle than that". And (yet more observent) "We're sideways to the waves, so we should be on a beam reach, but the yarn says we're still somewhat upwind".

Welcome to the world of apparent wind. This is a simple concept to explain and  understand at a high level, but very hard to get at a detailed level. Everyone gets the simple explanation - you're peddling a bike at 10 knots on a calm day, what do you feel? A 10 knot headwind. The speed you're generating adds to the wind speed to create the wind you feel, the apparent wind. The apparent wind is what you and the bike feel. Peddaling 10 knots in a 10 knot headwind, and you're pumping against a 20 knot apparent wind. Doing the same in a 10 knot tail wind, and Bob's very much your uncle.

Those with a math background easily grasp that this is a vector algebra problem - the boat wind speed adds up with the true wind speed as vectors, where both the speeds and the directions interact. But even if you get that, it's truly hard to see how it all plays out on the water. And I'm speaking as someone with a graduate education in mathematics. In editing this blog, I realized that I had messed up a calculation in my first draft. If you sit down to do the calculations, you have to determine what your boat speed will be at a given true wind speed and point of sail (angle of the boat to the wind). Polar performance diagrams will show this, but good luck finding these for any of our dinghy's.

So my point is that it's quite difficult to build a mental model of this. Instead, you can get a feel of how it happens on the water without trying to understand why, exactly. I did the math from a guess of a polar diagram for a boat similar to a Laser Bahia at 5 knots wind. If you're not racing, it doesn't matter how accurate this is. But it should be pretty typical.

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Michael Sherrell
The yarn on the shrouds will also tell you the precise apparent wind direction, in anything over a few knots.
Tuesday, 01 December 2015 13:07
Nathan Ilten
It would be a great senior project for someone to make some polars for our dinghies! There are enough people in the club with GPS ... Read More
Tuesday, 01 December 2015 23:06
Michael Sherrell
What is a "polar"?
Wednesday, 02 December 2015 07:36
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Teaching Upwind Sail Trim

Teaching Upwind Sail Trim

We have a teaching philosophy that is unique. Most sailing schools will do a "ground school" for hours before the students get on a boat. The idea is to explain how it all works, so the  student is prepared intellectually for the experience. Our approach is to get them on the water right away and have them just do it - steer the boat, tack, and get the feel for it.

I believe that our approach is correct, up to a point. You need some practice before the sailing theory makes any sense. And my experience as an instructor is that a beginning student will do just fine steering beam reach, tacking, even steering close-hauled without any discussion of how it all works.

The turning point is when they try to control the tiller and the main sheet at the same time. Lots of confusion, including understanding wind direction. Tacking from beam reach to beam reach and seeming to lose the wind (because the sails are trimmed too tightly).

This is the point where they really need an understanding of how it all works. And that's hard to do on the water. You  need an image to show how it works. I believe it's all pretty simple (or at least
can be explained simply), with a visual from above.

The key concept is that upwind (beam reach and higher) the sail is a wing, it works just like the wing of an airplane. Now an airplane wing has to be at a certain angle to the wind, or it doesn't work. Same with a sail. So when you're trimming the sail going upwind, you're keeping the sail at the same angle to the wind all the time.

Let's see what this looks like from above on several points of sail - close hauled, close reach,  and beam reach (click on the diagram to start the animation):

 

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Michael Sherrell
This animation is really cool, John. I just wish there was a way to summon it up at will while in the clubhouse during the pre-lau... Read More
Thursday, 19 November 2015 07:14
John Bongiovanni
I agree. In fact, I have just such a model (and a wind diagram) in my car. I used it today to explain slow-sailing on land. I mad... Read More
Thursday, 19 November 2015 16:36
Michael Sherrell
John, if you find some cheap enough at some toy store for example, please pick up one for me and maybe one for the clubhouse. We c... Read More
Thursday, 19 November 2015 20:06
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End of Season/Kid for a Kid party!

End of Season/Kid for a Kid party!

What better way to celebrate Sophie & Tudor bringing a kid into the world than roasting one...a goat that is!

Sophie & Tudor met at CSC a few years ago, got married, and are about to have their first child. It's a true CSC-style love story. Most know Sophie as our fantastic (co-)Port Captain and phenomenal windsurfer. What many may not know is that Sophie got her start at CSC in sailing and taught some of Tudor's first lessons...it's how they met! Sophie's still windsurfing like a boss in her final trimester - who would expect any less?

We hosted a party for Sophie and Tudor yesterday in celebration of the upcoming newest novice CSC member, along with the requisite delicious food. Oh and a bouncy house. Did we mention the bouncy house? (Pro tip: do not get in the bouncy house right after eating 3 desserts. Just, don't.) 

It's been a phenomenal season filled with lots of epic wind and novice sailors and windsurfers learning how to get around using this wind, thing - time for the deliciously warm months of Fall! :)

 

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Docking in Low Tide

Docking in Low Tide
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I posted while ago on launching in low tides. The idea was close attention to sail trim. The common mistake is to over-sheet the main leaving the dock, and even with full centerboard you'll drift sideways into the Cal Adventures dock.

Here I want to talk about docking in low tide. 

There are several problems. One is recognizing that it's low tide. It's easy going out with a "fresh" boat (you push the centerboard/rudder down and feel the mud, so you bring it up a few inches). But coming back you have to recognize and plan it. My rule of thumb for Bahias is that a tide of under +2.0 means you have to raise the centerboard and/or rudder. Plan for it, and raise both on the way in. When it's all the way down, the centerboard is about a foot lower than the rudder fully down, so you can adjust the two differently.  In very low tides, the rudder will be just below the water, horizontal. It will work, but it will be very  hard to use, and hard to turn quickly. Also, the stress on the rudder when it's parallel to the water surface is in a direction it's not designed for. So it's best to limit the amount of time you sail with the rudder in that position.

You will find that the boat handles differently with the centerboard up (or raised above the normal, fully down position). An important thing in docking is that the pivot point of the boat is farther aft, which means that where the boat actually turns in the water will also be farther aft.

The dock approach will be different in low tides. You can't use the standard "come in on a beam reach and slow sail to the dock". Your leeway with the centerboard up will be too much. Even if you aim for the south end of the dock, you'll be lucky not to hit the sea-wall (painful personal lesson here).

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Michael Sherrell
Alternate technique: Uncleat the rudder, keep your speed up, let the mud raise your centerboard, and plow through the mud! (Note J... Read More
Tuesday, 09 June 2015 11:20
John Bongiovanni
In a south wind, you'd be toast. Right into the seawall. The centerboard will still be dragging a bit in the mud, preventing you f... Read More
Tuesday, 09 June 2015 22:56
Michael Sherrell
That's probably true, but the idea would be to be on a line into the dock before you hit mud. A south wind would help drive you th... Read More
Friday, 26 June 2015 17:15
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Advanced Boat Handling - Another Great Advanced Dinghy Lesson

Advanced Boat Handling - Another Great Advanced Dinghy Lesson

The Advanced Dinghy lessons this year have been uniformly great.

This week's was no exception - boat handling by Jonas Kellner, a club member who's been sailing for over 30 years and teaching sailing and racing for almost as long.

Someone asked Jonas before the class whether he'd be teaching racing tactics. He said that he could, but knowing the best tactic for a given situation is useless if you can't execute the maneuver. He'd be focusing on the latter.

We had a pre-sail briefing, where Jonas explained what we'd be doing. 8 exercises around a set of buoys in a line perpendicular to the wind (so basically beam reach). The first and last exercises were slalom course, where we were to keep as tight to each buoy as we could.

The intermediate exercises were ovals around the set of buoys (counter-clockwise in all cases). They were technical exercises, designed to improve boat handling skills:

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Downwind sailing and the evils of rounding up

Downwind sailing and the evils of rounding up
One of the common pitfalls of sailing a dinghy downwind is that in a sudden gust, the boat will start to head up, leading to a capsize. In this blog post, I'd like to share some of my thoughts on the factors in play and how to best deal with them. This discussion applies to sailing with just main and jib, as well as to those thrill-seekers using a gennaker.
 
To begin with, why does your dinghy insist on heading up in a gust? There are (at least) two factors involved. To begin with, your dinghy typically has a bit of weather helm: to get technical, the center of effort (COE) on your sails lies slightly behind the center of lateral resistance (CLR) created by your dinghy's foils. In normal conditions, a bit of weather helm makes for a nice responsive tiller that helps you to better "feel" the boat and the wind. However, as the force on the sails increases as happens during a gust, the discrepancy between the COE and CLR is amplified, causing more and more weather helm. This effect will cause your boat to want to head up more strongly during a gust.
 
However, the natural weather helm caused by the discrepancy between COE and CLR isn't typically what will cause you problems. Instead, it is the additional weather helm caused by excessive heeling. Indeed, as the boat heels more, the hull's interaction with the water creates extra weather helm. Furthermore, your rudder is now only partially submerged, giving you less control over rounding up. And that is just the beginning: assuming that you are sailing below a beam reach, the more the boat rounds up, the more the heeling force on the sails increase. This causes more rounding up, which causes more heeling which causes... you can see that this will probably end with you getting wet.
 
Now that we know two of the main factors in play, let's consider three different scenarios.
  • First scenario: you're sailing on a dead run when a gust hits. The force of the wind on the main will indeed cause the boat to want to round up a bit. However, since you're on a run, it won't cause much heeling, so you only have the first aforementioned factor to deal with.
  • Second scenario: you're on a broad reach when a gust hits. Now you're in trouble -- you have both excessive weather helm coming from the force on the main, as well as weather helm caused by heeling. As you round up towards a beam reach, you can't depower the main, and you may end up capsizing.
  • Third scenario: you're on a beam reach when the gust hits. Again, both factors will apply, but as the boat rounds up above a beam, the main will start to depower, reducing heeling and weather helm and saving your bacon.
From the above analysis, we see that the danger of rounding up and capsizing is greatest when sailing close to a broad reach. But never fear: we have some powerful weapons at hand in combating the evil demon of weather helm.
 
First, we would like to be able to depower the main sail while sailing on a broad reach; this will decrease both natural weather helm and excessive heeling. Our first weapon for doing this is the vang or gnav. Easing this control in a gust lets the top portion of the sail twist away from the wind. While crewing for one of our club's most experienced dinghy sailors during the infamous Fast Track squall of May '12, my skipper had me blowing the gnav in every gust, and this is what let us limp back to the club in (more or less) once piece.
 
Our second weapon in depowering the main is of course the main sheet. If the wind is howling 20 knots and your Bahia is screaming along on a broad reach, chances are that your high boat speed is shifting the apparent wind far enough forwards that your main sheet should not be all the way out. The added bonus is that when the gust comes, you can now ease the sheet to help balance the boat and depower the main. If you instead neglected to sheet your mainsail in at all, you can't depower  by easing the main! 
 
Apart from depowering the main sail, the above analysis tells us that we want to do everything possible to keep the boat flat. Anticipating the gusts and aggressively falling off is key. Likewise, hard, aggressive hiking (or even sending crew out on the wire) are also important. Keep in mind, though, that if you are already hiking out hard before the gust hits, you won't be able to up the ante when you need to. Just as with the main sheet, it is highly advantageous to have a bit of room to make adjustment during gusts. Finally, aggressively sheeting in the jib (or gennaker) in gusts so that it stalls a bit will shift the COE forward in the boat, which will also decrease weather helm. Likewise, raking the centerboard aft slightly will shift CLR aft, also decreasing weather helm.
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John Bongiovanni
Great post, Nathan. One thing that I can't figure out is sheeting in the main on a broad reach. I guess the apparent wind has to ... Read More
Saturday, 09 May 2015 17:55
Nathan Ilten
John: Thanks! First of all, let's suppose that you've sheeted in the main "too far" so that the sail is stalling a bit. You are a... Read More
Saturday, 09 May 2015 22:41
John Bongiovanni
To reinforce something you mentioned but didn't highlight. I was out today with James C (great, wet experience), and he showed me... Read More
Saturday, 13 June 2015 20:37
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Advanced Dinghy Lessons Start with a Bang!

Philippe on the subject of sail trimming and especially use of the gnav (according to him, an under-used tool).

Philippe is an an incredible sailor and an amazing instructor.  We spent about half of the time on land with an RS Venture looking how the various sail controls affected sail shape and talking about what sail shape you want for what conditions (it was blowing over 15 kt. this evening, by the way, with pretty big seas - we  had a lot of weight on the boat on land to make sure it didn't capsize into the cars parked near the clubhouse). On land, it was much easier to see the effects of various controls on the sail shape.

This is my lesson summary (feel free to comment):

Scope: Dinghies which generally don't have travelers.

  1. Sail shape is very important. The usual things about depth and power, and location of sail draft. With lighter winds, you want a fuller sail and a draft a bit aft. With heavier winds, you want a tighter sail and a draft forward.
  2. In heavier seas, you want more power, even with stronger winds.
  3. Tensioning the Cunningham brings the draft forward.
  4. The outhall affects the lower third of the sail.
  5. Several controls bend the mast aft, which tighten the sail and move the draft forward. Tightening the mainsheet and the gnav do this.
  6. In high winds, you don't want the boom near the center of the boat, as the lift from the sail is mostly sideways to the boat. But just easing the mainsheet induces twist in the sail. Tightening the gnav overcomes this, allowing the mainsail to go to a better angle, but preserving the sail tightness.
  7. Bearing off from close-hauled, you want to do several things.  One is ease the mainsheet. Another is to keep weight on the windward side to help turn the boat downwind. A third is to ease the gnav (and then tighten it when on course).
  8. Gybe-ing:
    1. Blow the gnav before the gybe (this will depower the sail and cause the top of the sail to back-wind before the bottom of the sail, producing a gentler gybe).
    2. Weight the boat to windward to turn it down-wind through the wind. If you reach across to pull the boom across, you'll mess this up.
    3. If done correctly, the wind will gently pull the mainsail across. Grab the sheets as this happens to buffer it.
    4. Power up after the gybe by tightening the gnav

Then we went out and did it, both upwind and downwind. And it worked. I was prepared for hikiing really far out with the winds we had, but we didn't have to. And it was amazing how gentle the gybes were with this technique. Note that in bearing off and gbye-ing, you're doing what you would do rudder-less - moving weight to turn the boat. After the class, I discussed that with Philippe, and  his opinion (as a racer of some renown) is that the more you can use your weight to  maneuver the boat, the better (i.e. faster) you'll sail.

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John Bongiovanni
I want to add a couple of things to this. One is that I talked with Philippe today and asked hiim if I got it all right. He said ... Read More
Wednesday, 22 April 2015 19:52
Francisco Kattan
Thanks to John and Philippe for the great writeup and lesson. I've got some new things to try, especially releasing the gnab du... Read More
Thursday, 23 April 2015 18:07
Christian
Great stuff. Thank for the post!
Thursday, 23 April 2015 18:56
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A Sea Tale

b2ap3_thumbnail_nathan-ilten-robyn-gee-engagement-jan-2015.jpg

Unaware of what was about to transpire, the young woman on the bouncing bow clung grimly to the flailing pulpit, searching the horizon for a glimmer of hope. The young man knelt on the pitching foredeck behind her, fishing desperately into his bespoke West Marine foulies pockets for the unique object he believed would end the nightmare of uncertainty. Farther back, in the luxuriously appointed cockpit, the skipper and crew -- all ruggedly handsome -- fought to keep the Pierson Commander from broaching as the famed Emeryville abrolhos wind smacked the vessel, threatening to crush it into an equivariant toric bundle like you see in Macaulay 2. The man on the bow stumbled, lost his balance, and, crying out in what may have been Old Extremely Panicked German, tipped with his secret cargo toward the dark, beckoning waters off the port gunwale, unprotected by any Loos and Company lifelines, with nary a Harken chafe protector in sight.

This was the nightmare scenario. As it turned out, on a recent Monday, Anthony Lunnis, Paco Bellam, and I picked up CSC Senior Skipper Nathan Ilten and his guest Robyn Gee at San Francisco's Pier 1.5 and headed back to Berkeley without incident or wind, silencing the motor as we slipped past the Bay Bridge on a glassy sea as he proposed and she accepted on the foredeck of Portugal Princess.

 

 

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Michael Sherrell
May it be a long and happy one!
Thursday, 12 February 2015 10:31
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Low Tide Launching/Docking

Low Tide Launching/Docking

We've all experienced this, either as sailors or instructors.

You're going away from the dock, parallel to it, but somehow you're getting pushed sideways into the middle dock. Or you're docking, and you have a huge amount of leeway, pushing you into the seawall.

What I learned in the Advanced Dinghy class from Yves is that it's all about sail trim. Even with the centerboard completely down, you have a huge sideways force if you oversheet. Not only is the sail not as efficient as it could be, but the force is more sideways than forward. With the centerboard up (for low tides), the effect is worse.

This is the season of rip-roaring tides (it can go from more than 6' at noon to negative '1 at 6 pm, and the dock time has been as early as 3:30 some weeks).

Thanks to what I learned from Yves, I've been doing the following in my lessons when we had to dock with less than full centerboard. As soon as we get away from the dock, I raise the centerboard, and we sail, completely focused on sail trim. Jib is easy, mainsail more difficult (but more important). I try to get the students completely focused on sail trim. I tell them "They'll tell
you that you can't tack without a centerboard, but they're wrong" after they've tacked without a centerboard.

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Main Sail Trim by the Tell Tales

Main Sail Trim by the Tell Tales

There's a great book called Mainsail Trimming by Felix Marks that goes into this in great detail. A lot of it doesn't apply to dinghies (travelers, for example). But one thing does - trimming the mainsail using the mainsail telltales.

The telltalls are on the leech (back edge) of the sail, and when sailing upwind from a beam reach  and forward (when the sail is a wing), the tell tales should be streaming, just like both of the jib telltales. But what if they aren't? For the jib telltales, we have the guidelines "move the sail toward the telltale that isn't streaming" or "move the tiller toward the telltale that isn't streaming", and students seem to get that. But I don't think we talk enough about trimming the mainsail using the telltales (I could be wrong here, just my observation).

So (on a beam reach and above), if the mainsail telltales aren't streaming, they're curling to one side--windward or leeward. That's just like one of the jib telltales not streaming while the other one is. Move the sail that direction (as in, ease out if streaming to leeward and trim in if streaming to windward), or move the tiller that direction. Essentially the same thing as you would do to trim the jib.

I've seen a tendency in students to oversheet the main, so I think it's useful to sensitize them to this, and the mainsail telltales are one way to do this.

You can also use the mainsail telltales in a gybe. I went on the water once with Stefano Maffuli and a friend of his who had been head instructor at St. Francis Yacht Club (grazie, Stefano). He said that the mainsail telltales were the best indicator of when to pull the main across in a gybe. They show exactly when the main is back-winded--a much better signal than the jib coming across.

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Volunteer Spotlight: Michael Sherrell

Volunteer Spotlight: Michael Sherrell

[Photo courtesy of Seamus Vaneckohttp://www.seamusvanecko.com/gallery/sailors/]

Have you ever taken a dinghy lesson at Cal Sailing? Then chances are you have met Michael "Mike" Sherrell. He has been teaching lessons every Monday, Thursday, and Saturday for as long as I can remember. On innumerable occasions, he has saved the day, being the only instructor to show up. And as many club members can attest to, Mike is very serious about learning as much as he can about sailing, and then passing that knowledge on to his  students. 

Mike is a Berkeley native who, after retiring from biotech-related business, has the luxury of splitting his free time between sailing and his other passion, horses. In fact, he has four of them, and loves to go camping out with them. If you haven't seen him around the club recently, it's because he just got back from an epic camping trip in Oregon and Utah.

Mike was kind enough to answer some questions about sailing and his dedication to CSC

When did you start to sail, and what convinced you to try it out?

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A Couple of Capsize Recovery Tips

Appropriate capsize recovery techniques vary by wind speed, and there are several methods available for righting the boat  in situations where the wind is high and you are unable to keep the boat from re-capsizing. However if you can recover without setting the anchor or having a crew member swim around to the bow to line the boat up into the wind, the recovery will be quicker and easier.

To recover on the first attempt (without re-capsizing) with the least effort in the broadest range of conditions, here are two very useful tips.

First, uncleat the gnav/vang (in addition to the mainsheet & jib), as this will reduce the effect of the wind on the sail when the boat comes back up.

Second, while up on the gunwhale, before stepping onto the centerboard, consider what effect the wind direction will have on the boat once it comes up, and plan the effect the arrangement of your and your crew's weight will have on the boat's balance at that point.

  • If the mast is pointing away from the wind/hull is towards the wind, the crew will be on the downwind side when the boat comes up. Tell the crew to just hang on to the bungees under the gunwhale when the boat comes up, and then come around to the stern to get back in afterwards; when the boat comes up, the person on the centerboard tries their hardest to at least get half way over the gunwhale so as to keep the upwind side weighted down.
  • If the mast is pointed towards the wind (a situation in which a double capsize is very common), the crew will be on the upwind side when the boat comes up. Have them hang onto the hiking straps as the boat comes up so their bodies are draped over the gunwhale. If they  weigh enough--taking the wind's power into account changes the meaning of 'enough'--the person on the centerboard can dry recover, particularly if he/she scrambles quickly across to the upwind side. If the crew is lighter than the person on the centerboard, the person on the centerboard should plan to go down into the water and get back into the boat from the stern (holding on to the boat at all times). 

Under almost all capsize conditions where you're not right by a lee shore or dock, the person on the gunwhale can take as long as they want to consider the situation and to discuss it with the rest of the crew. 

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Yves Parent
In addition, Seamus's trick to easily board from the stern works very well. In this push yourself down in the water and use the mo... Read More
Monday, 18 August 2014 23:21
Francisco Kattan
Nice post, thank you. What is the ideal position of the outhaul during capsize recovery? Tight or loose? and why?
Wednesday, 20 August 2014 09:30
Michael Sherrell
Francisco, never gave the outhaul any thought. It is only tensioned under full sail, of course. If blowing the gnav/vang helps, I ... Read More
Wednesday, 20 August 2014 10:28
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How to Trap Single-Handed (video)


1. Wear comfortable, non-restrictive gear and as many temporary pirate tattoos as possible.

2. Get a really, really long tiller.

3. Have awesome background music. 

4. Get out there.

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Camille Antinori
Nice video. Like the weight placement. I would add that nice grippy trapezing boots are really handy. I am wondering if my new ... Read More
Saturday, 23 August 2014 12:52
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