You bring up an intresting point about the H20 tank. Earlier this year I finished second in one race. After the race, I found the anchor
locker drain plug blocked and the locker about 14" deep in H20. I thought that draining the tank would help - maybe not! Going down wind is easy. Just prior to rounding the mark set up the vang as a preventor on the toe rail. Run wing & wing as close to dead downwind as possible but with the wind just off the opposite side of the main as possible. All the air off the main bounces into the headsail.