sorry to cut in here when i'm not a wave rider? but i'd thought i'd toss these bits onto the fire

i just about always sail with my etrex legend gps on the boat and then download the data to my laptop to compare with previous tracks, speeds etc great tuning help

i'm hoping to see some improvements to my nacra 5.2's pointing ability once i start raking the mast back

as to speeds, solo sailing on a 17 foot nacra like gree's i find that the windward hull wants to start to fly around 14kph, 8.7mph, 7.5knots with my 150lbs sitting on the windward hull. leeward bow still well clear of digging in

max speed so far has been 30kph, 18.9mph, 16.4 knots. and that was without a trapeze but well back on the windward hull meets rear beam join. hoping to take that higher when i get a full trapeze harness, foot straps on the rear hulls and a way of righting a 2 man cat solo

have attached a gps screen grab. the tracklog data shows the leg speeds either side of the top speed to been 15knots so i think it's pretty reliable

to put things into perspective this quote from the catapult website might help

"Catapult Sensationally fast for a 5m (16ft–4in) boat - 17.03 knots at Weymouth Speed week with peaks of over 20 knots."