Sue,

Life is not as simple as you say. But okay, I will use your simple formula f=m*a.
If your boat accelerates slower because it is neavier, then it deaccelerates also slower.
Let us assume, both boats (one is 10% heavier) sail with 17kts. Both boats are hit by a wave (or a lull or make a manoeuvre or whatever) at the same time.
The speed of the normal boat slows down to 15kts. (17kts - 2kts/s * 1s)
The heavier boat slows only down to 15.2kts, right? (17kts-0.9 * 2kts/s * 1s)
Now the boats accelerate again.
After one second the normal boat reaches again 17 kts. (15kts + 2kts/s * 1s)
The heavier boat accelerates slower, but because it has only lost 10% less speed, both boats reaches at the same time the speed of 17kts. (15.2kts + 0.9 * 2kts/s * 1s)
During all this time, the heavier boat had have an equal or a higher speed than the lighter one, and hence traveled a longer distance.
It is logic that a boat has to accelerate after each de-accelertaion. Hence from start to finish we have n de-accelertions and n+1 (the +1 is at the start of the race) accelerations. So the hevaier boat makes n times something good and looses only one time something.

Of course life is not only F=m*a, the hydro- and aerodynamic characteristics cannot be neglected. But even in your simple model, a heavier boat is faster.


Not only to Sue:

So far, it is an interesting discussion with good arguments from all participants. Let us discuss in civilised way, without insulting each other please.

Cheers,

Klaus