Saturday, March 29, 2014

Spring sessions

I have received thinly veiled complains that I don't blog about our sailing enough recently, so this is a catch-up post. It's long and boring, so let me start with how interesting things could have been:
That's Jerry jumping at Coast Guard yesterday. The waves were small, but that did not keep him from having fun:
Coast Guard is an ocean beach. Our home beach, Kalmus, is not - it's in Nantucket Sound. Two islands 30 km to the south, Nantucket and Martha's Vineyard, keep ocean swell away. The Hyannis Port breakwater about 1 mile to the southwest keeps the chop down. But in SSW winds like we had yesterday, the big difference is that the wind in Kalmus is straight onshore, but at Coast Guard, it's side-offshore. With water temperatures just above freezing, that matters to me. I think it should - Nina and I both managed to kill sails in our recent sessions. Offshore winds, equipment problems, and cold water don't go well together. Side-off wind is a little better, but just a little.

When spring comes, many windsurfers around here start feeling slightly schizophrenic. On one hand, we love it when we get warm southerly winds. On the other hand, cold water and warm wind means that we may sit on the beach and stare at windless water: the dreaded decoupling happens! If the temperature difference is too big, the wind "decouples": as it approaches the shoreline, it lifts up, leaving us windsurfers windless. This happens when the wind is onshore or side-one; on offshore and side-off beaches, it does not happen.

Yesterday's air temperature was near 50ºF (10ºC), but the water temperature was closer to 36ºF (2ºC).  Decoupling was a definite possibility. But around noon, the wind picked up to 25 mph. I was on the water 90 minutes later, and had some fun on a 5.3 m sail. For me, that counts as a small sail. Things were fine for half an hour. They even seemed to be getting better as the wind increased - until I forgot what I had posted here 2 weeks ago, and practiced my karate skills on a sail again. Well, it was really more a slow tai chi elbow during a really slow fall, but the sail did not like it, not one little bit.

Back to shore to re-rigg. I picked the 5.0 this time, only to see the wind go down. Tried the bigger board, but the wind was watching me, and went down even more. Just about then, Nina was ready to go out on here brand-new four point two. Nope! She took my 5.0 and her big Skate instead, and I rigged a third sail - 7.0 this time.

When we hit the water, the wind was just about perfect for our sail sizes. With a negative low tide, water depth was rather similar to Bonaire, so Nina went and did her thing - duck jibes, push tacks, a few duck tack tries, and donkey jibe tries. Her duck jibes looked great (as usual), and her donkeys were getting really close. I just worked on jibing (yes, again/still!). During a recent session at the Kennedy Slicks, I had a hard time planing out of my jibes, despite being nicely powered (albeit on 7.5). To figure out what was going on, I took some clew view GoPro footage. This is what I saw:
This is mid-jibe, shortly before the foot switch. Both arms are bent - it looks like I'm trying to pull the boom straight through me. This is not how your are supposed to do this! The front arm is supposed to be extended! My knees are bent just enough so that I did not hook in again (despite long harness lines), but this stance kills speed. Here's what the GPS showed:
All my jibes were dry; I often picked up speed as I entered the jibe; but I lost way too much speed mid-jibe. This picture shows why:
With both arms bent, I am pulling the sail back onto me. This makes the tail sink and the nose rear up, slowing the board down. Funny thing is - I did not realize I was doing this! But it's an old and recurring habit - here's proof from our Tobago trip:

Of course, this is absolutely, positively not my fault! I can find many others to blame for this. Maybe I am just mixing up a few different bits of advice here: "pull down on the boom during the jibe", and "to pull down on the boom, the elbows need to point down". Taken separately, these two pieces of advice make sense; put together in the middle of the jibe like I did, they are bloody nonsense!

I am doing this same stupid thing just about every single time I jibe, even though I know it's wrong. This is completely automatic - chances are I have done this for years without noticing. So in yesterday's session, my only focus in jibes was to keep the front arm extended. I tried to go for Dasher's advice: "the hips roll in, the mast moves to the outside", concentrating on keeping the arm long. That worked ok - but I'd still catch myself starting with extended arms, then quickly bending both arms, and then extending them again just before moving to the inside. Muscle memory from years of doing it wrong are hard to replace!

Towards the end of the session, I found myself getting ready for another beach start with the rig in hand, but no board attached. Seems the board had had enough of me and decided to go back to shore. Since the water was just knee deep, I caught it quickly and made sure to use a bit more force on the mast foot this time. I was, however, rather glad that I had not gone to sail in side-off wind! The board would probably be on its way to Europe now...

Now back to the question what the wind did yesterday- did it decouple? Well, the wind was up and down, peaking at averages near 30 mph, and then dropping down to less than 20 mph. However, it did exactly the same thing at Chapin on the other side of the Cape, where winds were offshore. That indicates it was not decoupling this time - on a decoupling day, the Chapin meter would show stronger and more consistent wind. Looking at the other wind meters confirms this: both the Chatham (onshore) and the Hatch Beach (side-offshore) meter showed consistent winds; the West Island meter, which juts out into Buzzards Bay and is not prone to decoupling, showed wind patterns very similar to Kalmus, but a bit weaker. On many SW days, the West Island meter reads higher than Kalmus due to its exposed location. So it seems that what we had yesterday was something that is often seen in the wind forecasts: the wind simply was much stronger further out (eastward) on the Cape. The huge high that was driving these winds was a few hundred miles to out east, so this makes sense (kind of).

Well, I warned you that this would be a long post, so I'll just keep going. Edda needs to know all the details about our windsurfing, after all! Our last windsurfing session before yesterday was exactly a week ago. It was also a south wind session, and the wind was just as temperamental. It stayed around 30 mph for a bit more than one hour, and I got to enjoy some of that on a 4.7m sail, fully powered. Last week's forecast actually had predicted a quick raise and drop in the wind, and that's what we got. Martin arrived just as the wind was ramping up, and ended up rigging three sails, only to end up with just a couple of runs on his 4.2 before the wind dropped. After a short deep drop, the wind stayed around 25 mph for almost two hours, but by then, everyone had given up. Nina had a lousy day on her 5.3 - underpowered at first, and overpowered 20 minutes later. Her confidence was still a bit shaken from breaking a sail in the previous session, so that was not her day.

Two days before that, I had a short and sweet session at the Kennedy Slicks. I was on big slalom gear (117 l + 7.5 m) to practice for the ECWF Long Island in June, which was just perfect for the conditions. Once again, the wind was fluky, but I was lucky with my timing and got a nice one-hour session in. March started slow with no session in the first 11 days, but with 6 sessions since then, I can't complain. And there's still hope for one more session on Monday :-).

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Pete commented that many problems in jibes being from bad entries, in particular not oversheeting enough. I agree that is is often true, but it is not what slows me down these days. Below is an image from one of the jibes from the Kennedy Slicks session. 

So far, so good - the sail is oversheeted and pushed out of the way, the front arm is still long. But two seconds later in this jibe, as I open up the sail, my front arm did indeed bend again, and I lost speed.