Hi Steve,

With regards to your question about extra weight only, an extra 5 kg means an extra 5kg your boat must displace (move an extra 5 ltrs of water.

Where this is the most noticable is downwind in light through to heavy conditions. The lighter the weight the deeper you can send it down wind = better VMG. That is why in the most competitve fleets you see the good sailors trying to keep their boat weight to the absolute min with crew weight also to the min or to the optimum weight (not weight range). It does make a BIG difference on the race course, trust me. Of late I have raced the F18 with crew weights between 184 kg to 135 kg in amoungst quality fleets, but mostly around the 150 to 160.