Your Anchor is your Friend

Your Anchor is your Friend

I admire David Fraser's willingness to share his "less than optimal" sailing experiences in these blogs so that others can learn from his mistakes. They say there are those who don't make mistakes (I don't believe that), those who learn from others' mistakes, those who learn from their own mistakes, and those who never learn. Aiming at the second category, I want to imitate David's example by offering a recent experience of my own.

The other day I got to the Club a little early, and thought I'd play with jib-only sailing on a Quest before lessons started.

I left the (Cal Adventures) dock under jib only, having done nothing with the mainsail. I was planning to go out and dock under jib alone a few times before students showed up. That was the plan, at least.

The wind was pretty much westerly, so I was leaving on a beam reach. I knew that jib trim was really important, and that I shouldn't start out pointing too high. But for whatever reason, I couldn't point high at all. No matter what I tried, I was going slowly downwind, toward the rocks. Maybe I wasn't handling it correctly, maybe the Quest can't point high on jib alone, who knows? Sometimes it's you, sometimes it's the boat, sometimes... who knows what it is? What mattered then was that I couldn't do it.

I decided to heave to and get the main up, admitting failure (better than landing on the rocks). The mainsail doesn't always go up easily on the Quests (especially on this one), and it looked like getting the boltrope into the mast track might take some doing. When you're properly hove to, you have some sideways way on--that is, you're slideslipping--and I was going slowly, slowly toward the rocks. I had no idea how long it might take to get the main up.

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Recent Comments
Rama Hoetzlein
Thanks for the interesting story. Based on these experiences, I wonder if you have any tips on what to do differently to sail upw... Read More
Tuesday, 11 July 2017 23:11
John Bongiovanni
What I didn't say in the blog was that I went out a few days later and did much better, as the purpose of the blog was the importa... Read More
Friday, 14 July 2017 17:28
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The two-handed drill for puffs and lulls

The two-handed drill for puffs and lulls

A while ago, James Clarkson recommended one of Frank Bethwaite's books on sailing to me. I forget which one, as I now have three of them. They're incredible but incredibly dense, so I'd only recommend them to the "quants" of the sailing community. And even then, you'll read a lot more about  weather systems than you ever wanted to learn, and more detail on everything than you can comprehend. That's how Frank was. He was a pilot (of commercial flying boats, think about that), a meteorologist (the official metereologist of the Austrailian Olympic team in several Olympics in the 1970s), and a sailing fanatic as coach and designer. Three of his kids (sons and daughter) won Olympic medals, and one of them may have invented the gennaker (as always with inventions, there are priority disputes). Frank died in his 90s in 2012.

For the patient reader, there's really wonderful stuff in his books. One is an explanation of why sail twist needs to be very different in light winds than in higher winds (another post?). And there are many others.

One very practical thing I got out of his books was a technique and a teaching technique of how to respond to puffs and lulls. We all know how to do this, we do it, and we teach it to some extent. You have three controls: weight placement (out in a puff, in in a lull), tiller (pinch in a puff if the boat can do it, fall off in a lull), and sheet (easy in a puff, trim in a lull, not just mainsheet, but also jibsheet if you're really concerned about speed). I tell basic students that they have these three controls, and to use one or more  of them when they get a puff (at this point in their development, they're not so worried about lulls).

Frank was obsessed with keeping the boat flat and as fast as it can go (these are correlated). Assuming a decent wind, you're hiked out. We're assunming you have the tiller extension in one hand and the mainsheet in the other. A puff will heel the boat to leeward, and a lull will heel it to windward if you don't move your weight in either case. His technique is this: when the boat heels, don't move your weight, but move both hands to the down side, the sheet hand more than the tiller. Never luff.

So in a puff, you're easing the main as you're pointing slightly upwind. In a lull (or in the recovery after a puff), you're doing the opposite - sheeting in the main and pointing slightly downwind.

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Ready, Set, Wear It! Life Jacket World Record Day

On May 20, 2017, Cal Sailing Club members will gather with boating safety educators, marine enforcement officials, politicians, media, and the general public across North America and throughout the world to try to beat the 2015 world record of 10,917 life jackets worn and inflatable life jackets inflated. Ready, Set, Wear It! Life Jacket World Record Day aims to raise public awareness of the importance of life jacket wear and general boating safety practices.

Screen Shot 2016 06 24 at 1.10.52 PM

Please join us starting from 10am: wear a life jacket, take a picture and help us break the record! A Cal Sailing Club volunteer will help with questions about the value of life jackets and collect your picture.

The event will officially launch National Safe Boating Week, which occurs from May 20 – 26 this year. This timing positions the campaign just before the Memorial Day weekend, the “unofficial start of summer” when in the upper states the water is dangerously cold and throughout America, historically, many boating incidents occur.

Ready, Set, Wear It! events, including inflatable life jacket demonstrations make for great TV and photo opportunities, but it is just the beginning of the North American Safe Boating Campaign message. The purpose of the event and the yearlong campaign is to raise public awareness of the importance of life jacket wear and general boating safety practices. The event is coordinated by the National Safe Boating Council (NSBC) in partnership with the Canadian Safe Boating Council (CSBC) along with their respective members and affiliated organizations.

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Wear Your Lifejacket To Work Day 2017

Friday May 19, 2017 help get the word out about life jackets!

Join your colleagues, peers, and friends around the world in demonstrating how easy it is to wear a life jacket - even at work!

Just prior to National Safe Boating Week and the day before the eigth-annual "Ready, Set, Wear It!" event, we are asking you to take a photo of yourself wearing your life jacket at work on May 19!

Don't forget to post your photo to Facebook.com/ReadySetWearlt or tweet @ReadySetWearlt and @CalSailing using #readysetwearit to show off your style.

SZX2KOF

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An important fine point on Docking in Low Tide

One of the things I love about sailing is that I learn something every time I go out, I'm constantly expanding my knowledge and skills.Talking with several of the very best sailors in the Club recently, I heard the same sentiment.

We're in the season of low tides and early closings, and I learned something about low-tide docking.

I did a blog post a while ago on docking in low tide. I recommend looking at this post, as you need to dock in a completely different way than you normally do. You come in way upwind instead of downwind, and you don't (can't) slow sail (you'll just get pushed sideways into the seawall).

In the present post, I want to amplify a small but important detail, which I discovered recently docking in low tide (wind from the east in this case, but that doesn't matter). I was following more or less the course I recommended in the earlier blog: go upwind, downwind past the dock, and then shoot up:

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SAILING AT THE SUMMER PALACE

© 2017 DAVID FRASER

Ever since my dad took me, age 10, out in a dinghy in Regent's Park Lake in London and we were becalmed for an hour, I have loved sailing. So when traveling rough through China years ago with a friend from the Bronx, we spotted a dinghy rental place on a shallow manmade lake north of Beijing, it was impossible to resist.

Kunming Lake graces the Summer Palace, the suburban 19th century watering hole of China's emperors escaping the dry summer heat of Beijing. Breezes and greenery helped keep the Qing Dynasty royals and their retainers from sweating overmuch, and it is said they popped into the lake for a swim before cocktails in the evenings.

Dominating the shore was an extraordinary creation, the Marble Boat of the Dowager Empress Ci Xi, she of the long fingernails and longer political reach. In 1893, despite foreign occupation of China and the shadow of a rapidly industrializing war-hungry Japan, Her Majesty ordered the rebuilding of the boat, a two-story structure complete with fake paddle wheels. The royally embezzled funds were supposed to go to build a modern Navy.

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Why Winter Sailing can be a Great Learning Experience

We are blessed in the Bay Area with incredible summer sailing conditions - 15 to 25 kts every single day from the West to South-West and waves to match. What could be finer?

Fall-Winter-early Spring is problematic. The system that creates the big daily summer winds in gone, so the winds are typically very light, except in storm systems, where they can be over-whelming (35-40 kts, typically from the South). So many just don't sail in the winter. I think this is a mistake, for at least two reasons.

One is that you learn an awful lot about sail trim and boat balance sailing in lighter winds (5 kts or less).

Everything changes, from the way the winds are produced atmospherically to how you set the sails. For example, in lighter winds the wind at the sea surface is practically zero, and difference between the wind there and the wind at the top of the mast is (relatively) large. So you're getting most of your power from the top third of the sail, which you want to keep happy. In higher winds, there isn't that much difference between surface wind and wind at the top of the mast.

In very light winds, the wind may not be strong enough to hold the mainsail and boom to leeward. So you need weight to leeward to tilt the boat enough so that gravity pulls the sail to leeward and forms the sail shape. With the sail shape formed, the wind will power it. And the battens bay not flip on a tack or gybe, so you might have to shake the sail to get that to happen.

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Recent Comments
Ryan Alder
We had some really good 15-20knot Southerly winds this weekend, which makes for exciting docking. We get spoiled being in the win... Read More
Monday, 20 February 2017 11:40
John Bongiovanni
Great technique, Ryan. I'll add that you can practice the maneuver before you get to the dock to see how the boat will handle whe... Read More
Wednesday, 22 February 2017 19:54
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End Of Summer Delta Trip

End Of Summer Delta Trip

I'd visited the Delta 3 times previously - all for the ABK windsurfing camp; on the last two occcasions I had organized the trip - and I can tell you, trying to get more than a few windsurfers in one place at the same time with a cohesive set of gear is a challenge.  Being a sucker for punishment, and never having sailed Sherman Island outside of ABK, I organized a club trip back in September for end of summer.  This is a recap.

In the run up, I'd had interest from over 20 indivuduals.  There's usually a lot of attrition and these events, and worse, as the day drew near, the forecast was for sun, but little wind.  At the final count, we ended up with 8 - Myself, Wayne, Dora, Ceci, Christina, Zach, Jamie and Will joining us in the afternoon.   We met at the club bright and early, and loaded up with more gear than we thought we'd possibly need.  As it turned out later, we did need it.

We set off for the hour or so drive.  Even with GPS, where to go isn't completely obvious - after crossing the bidge in Antioch, you drive for about 2 miles, then turn off along a narrow road along a river embankment for a further few miles.  At the end are some new (this year) confusing one way systems and lots dirt due to ongoing construction.  The park itself is at the end, and is $5 to go into the parking area by the "playpen", which is the nominal novice area.   Only Christina and Jamie managed to get slightly lost, but not for long.

As we rigged up, the extra gear we'd broght came into use.  Ceci's sail had no pulley - oops!  Winching the downhaul on Dora's sail, on a non-matching mast, we put the top through the mast sleeve.  Oh man!  And finally, one of the booms was lacking a head.  In the end, everyone ended up with workable gear - at least as much as the wind would allow.

I had hoped to teach some beachstarting - Sherman Island is fantastic for this - but the morning wind barely topped 3-4 knots, so it wasn't really to be.  Despite that, both Christina and Ceci, with some lucky gusts and a little encouragement, did in fact achieve their very first beach start - hooray!



Ceci had graciously offered to prepare both lunch and dinner - also facilitating my vegan requirements - as it turns out, the non-vegan echiladas had been placed too close to a bunch of ants, and had to be picked out!  However, both the enchilads and later, the curry (thankfully non-spicy), despite their simplicity, proved to be a hit with everyone, after some ingeious cooking on the tiny camp stove.



In the afternoon, the wind really died, to perhaps 2-3 knots, and we were reduced to some low-wind practice.  I did venture about half way out in the river to the river marker - not something I'd attempt if there'd been much current (the delta has some quite strong tides), and we were the only sail power on the river; a couple windsurrfing in the morning had gone elsewhere.


Zach showed us some fancy backwinding, and we also saw all kinds of funky things in the river, including both live and dead fish!  Also, strangley, there was an interrmittent "burping" sound, which could not be identified - no doubt a river monster or somesuch.
Apart from the lack of wind, it proved to be a beautiful day.  Unfortunately, a vist that time of the year is always going to be subject to the capriicious wind gods; and although in recent years there has been wind at the end of September, it was not to be.



No matter.  We'll be back.  I'm already planning a trip for Spring.   The ABK California schdule for 2017 has yet to be decided, but that will likely happen at the end of summer too.

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New Wetsuits Have Arrived!

New Wetsuits Have Arrived!

 

The club has new wetsuits from Xcel Wetsuits and so far they've been a smashing success with sailors and windsurfers alike.To keep our wetsuits from turning into swiss cheese, take a moment to review the guidelines for wetsuit wear at CSC:

 - Find your size - hold up a suit to your body and see if the crotch and neck line up, that's a good starting place. Your wetsuit should fit like a glove, but not like a noose - if it won't zip, get a larger size. Wearing ankle socks will help the suit slide over your heel so you don't have to yank on it with your sharp fingernails.

 - Wear a bathing suit under your wetsuit - you never know when you'll end up with the suit with the peekaboo crotch, and being able to strip down to swim trunks makes it easy to rinse off your wetsuit when you come off the water.

 - Sailor must wear foulies over wetsuits - dinghies are the #1 cause of butt tears, stretched groins, and random punctures - even walking around in the crowded boat yard can be hazardous to wetsuits. Wearing foulie overalls over the wetsuit greatly increases their longevity and helps us save money for things like those shiny new Quests.

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Rigging a Bahia's Reefing Line

I've had to correct mis-rigged Bahia reefing lines recently, so I thought I'd explain how to rig the line properly. You'll have to do this if the main sail is crunched at the leech when you raise it fullly or if you can't fully reef the sail.

It's a little confusing, as it's two lines in a "jiffy reef" system, so that you only have to pull on one line to pull down both the luff and the leach of the sail. But once you get the picture, it isn't that hard to deal with. Here's what it looks like:

The line through the leech of the sail attaches to a block in the boom. The line through the luff of the sail runs through the block and back out the forward end of the boom through the cleat.

So what happens when you reef is this. You pull on the line at the forward end of the boom. This pulls the block attached to the leach line forward through the boom, pulling the aft reefing line down and raising the boom to the reefing gromet. You get here:

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Recent Comments
Ryan Alder
Nice description on how to get the right length of the two lines attached to the block! Not knowing the technique, it takes a lot... Read More
Tuesday, 06 September 2016 14:22
John Bongiovanni
The diagrams are based on the Bahia manual, so they're the manufacturers recommendations, for whatever that's worth. However, I b... Read More
Tuesday, 06 September 2016 15:52
John Shearer
Hi John! Excellent guide on the reefing process! I have to agree with Ryan on the routing issue. If the manufacturer recommende... Read More
Sunday, 13 November 2016 15:41
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Heart Health: CSC has an AED!

Everyone knows sailing and windsurfing are good for the heart. Even so, CSC periodically sponsors First Aid classes to keep club members knowledgeable of what to do in an emergency.

Back in June, CSC sponsored a CPR/first aid class that went over the new standards in CPR and first aid, and also taught us how to use an AED  (automated external defibrillator). 

Heart disease is still the leading cause of death in the US, accounting for 1 in every 4 deaths.

The most common reason for a sudden cardiac arrest is ventricular fibrillation, which is an arrhythmia that interferes with the heart’s ability to beat properly and pump blood. We were advised to start with CPR (which circulates blood in the body), but a shock from an AED can restore a heartbeat if the arrhythmia is one that's "shockable". 

After taking the class, one of our Executive Committee (Excomm) Members, Joel Gussman, took up the special project to get an AED for the club. Thanks to his efforts, we now have one set up and ready to use in the clubhouse!  In an emergency, we should always call 911 right away, but while we wait for emergency vehicles, we have CPR and the AED to try and help improve the victimes survival chances.

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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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Recent Comments
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

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

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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Recent Comments
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

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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Cargo Cult and the Drudgery of Maintenance

Cargo Cult and the Drudgery of Maintenance

"Early theories of cargo cults began from the assumption that practitioners simply failed to understand technology."

New members often express bright enthusiasm for learning to maintain our equipment.  It's common to hear prospective members say how much they want to fix windsurf boards, sailboats, and other gear.

Which is great.  Maintenance by volunteers is a central part of Cal Sailing Club.  It keeps costs low, it teaches a lot about the equipment, and it's a different kind of fun than sailing in a boat or just watching the water with others.

What is the attraction for these bright-eyed would-be Mr. & Ms. Fixits?  Maybe they think that learning it will enable them to have complete mastery of the equipment--ding-free windsurf boards, sheets that zip through blocks with zero friction, outboards that unfailingly leap to life.  Maybe they think they'll become experts, sail around the world on a tiny budget thanks to their clever repairs, keep a quiver of windsurf boards and sails in tip-top shape for pennies, and be able to take on any repair with complete confidence.

If so, they're right, kind of.  If they hang out long enough and do enough work, they'll get pretty good at fixing stuff, and they'll save money on gear and keep it in better shape.

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Demystifying Apparent Wind - Part 3

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:

b2ap3_thumbnail_Apparent-Wind-Downwind.gif

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Demystifying Apparent Wind - Part 2

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:

b2ap3_thumbnail_Apparent-Wind-Puff---Close-Hauled.jpg

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:

b2ap3_thumbnail_Apparent-Wind-Puff.---Puff.jpg

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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

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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Recent Comments
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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