Spinnaker control in high winds

We’ve only had a few opportunities to fly the kite on really windy nights.  Each time it seems we learn something more.  I also talked to some of the other skippers last night after the race to pick up some more tips, so I thought I’d try to systematize what we have so far.  The risks seem to come in two forms: when sailing deep angles, we have to avoid death rolls; when sailing higher angles (like last night), we have to avoid broaching.

First a description of each:

• Death rolls are a lateral oscillation that starts up and grows.  The boat starts rocking back and forth, and gets difficult to steer and control.  If the rocking isn’t diminished it could lead to a broach.
• Broach is when the boat starts heading upwind with a mind of its own.  As it goes upwind, it gains more power, and like weather helm, it then continues to go higher. Meanwhile the boat begins to heel excessively and the rudder has absolutely no control over the steering.

Remedies

• Avoidance:  The best way to handle these circumstances is to avoid them.
  1. Anticipate the gusts — have someone spotting the wind and alerting everyone to a gust that might be on its way.  Calvin did a great job of that last night when we were able to ride a gust properly and set our speed record.
  2. Steer properly — steer to a lower heading just as the gust is beginning to build.  This way as the boat accelerates, the apparent wind angle doesn’t shift forward.  Done properly, the boat surges forward at great speed, but stays in balance.  This was the case when we set our speed record.
  3. Depower the sails — spinnaker pole low depowers the spinnaker, and easing the boom vang enables the mainsail to spill wind.  We probably could have done a bit more of these last night.
• Reaction: A quick reaction can sometimes reverse the trend  (Here’s a nice video of reacting to a broach)  It boils down to this sequence:
  1. Mainsail
     1. Ease boom vang (they call it a kicker in the video) — done early, it might be enough!.  Easing the boom vang allows the mainsail to spill wind which depowers the mainsail, and shifts the center of force forward, so that the rudder can start steering again, and a would-be broach turns into a surge of speed in the right direction.
     2. Ease the main sheet — done early, it might be enough!
  2. Spinnaker
     1. Ease the sheet — done early it might be enough!  A couple feet of line could do it, then when the boat is level again and steering is re-established, trim on and away we go.
     2. Blow the sheet!  Sometimes, that’s just what we’ll have to do.  We should NOT have stopper knots on our spinnaker sheets and guys.
• Recovery — if things have simply gone too far…
  • Blow the spinnaker guy and halyard.  The spinnaker will land in the water, but that’s okay so long as we have a stopper knot on our halyard we can retrieve it.  Yep, we’ve done that before!
  • Have a knife handy for a last resort.  Cut the halyard and let her go.  Better to lose a spinnaker than a boat.  I have a knife in the bag under the helm for just this kind of purpose.

And one nice piece of wisdom I found online: