Tuesday, 2 June 2015

Sailing between the holes

The Ottawa River isn't particularly wavy.  Most days, the wind blows from the west, and generally follows the river.  This means the waves are not as big as you'd expect for a given wind speed, since the difference between wind and water is (wind_speed - current_speed).  When it blows from the south or east, however, the waves are bigger since the different between the wind speed and the water speed is (wind_speed + current_speed).

I had the opportunity to get some wave-practice in last night.  The wind was coming up river, and the waves were a good 3 feet high with whitecaps.  Since I don't have a lot of experience in waves, this was a good chance to try different things, and see what works for me.

The wind and waves were going slightly different directions, meaning that on port tack, on a close hauled course, I was just about perpendicular to the oncoming waves.

Attempt 1: baseline attempt - sail close hauled as if there no waves
Nope.  I'd go up a wave (slow down significantly), past the crest, and the bow would come crashing down into the trough [splash!].  The next wave would then hit my bow full on, crashing over the top of the deck, and stopping me (or pushing me backwards!).  Apparently, the Laser does not have a wave-piercing hull.  :)

Attempt 2: use body weight/position
Here I tried to shift my body weight to allow for smoothing wave crossings.  At the top of the wave I'd be low down, and hiked out far.  In the troughs, I'd be sitting higher.  My thought was that if my centre of mass was relatively stable (from a vertical perspective), then the wave would only be moving the boat up and down.  This would mean the wave would have an easier time lifting the boat.

This had a bit of an effect, but not as much as I was hoping.  I then tried moving my body back-and-forth (fore-and-aft) to try to force the boat into/through/up/down/the waves in various ways.  Again, this seemed to have an effect, but I had trouble getting the timing of what to do, when, correct.  The is something I should practice, and try to get a better handle on, as between the up/down and fore/aft movement, the waves could probably be much more manageable.

Attempt 3: steering to avoid the holes
I noticed that the biggest trouble stop was not the big-wave-coming-towards-me, it was that I'm-stuck-in-this-deep-trough-when-the-wave-hits.  I tried something new -- when I saw particularly deep trough coming towards me, I bore off slightly to avoid it.  I tried to point between the peaks of the next wave, as the bigger the crest, the bigger the trough behind it.

This was REALLY effective.  Not only was avoiding the brakes of "pitch-poling", be the few seconds of bearing off also increased boat speed as I was on a bit more of a close reach (rather than close hauled) and I could pinch a little bit immediately after to make up for lost pointing.  Practising this, along with better body movement should definitely improve upwind/big-wave performance.

In the diagram, you can see something like my original close-hauled course in red.  At each "break" in the line, is when I'd crest a wave, crash down, and almost stop.

The green course shows me bearing away when I see a "pit" coming.  While it's not as close to the wind as the red course, I found it much faster.

The takeaway:
- Steer to avoid the deep pits and troughs
- Bear off to increase speed
- Avoid digging the bow into oncoming waves
- Try to figure out how to use body weight/position/movement

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