Am 19.07.23 um 14:07 schrieb Taco Hoekwater:
> First, find the actual point along the curve of the wave you want, then you can ask for the direction of the wave at that time, and its point:

Thank you!

> pair itime, iangle, boatpos;
> 
> itime = (wave[3] intersectiontimes ((xpos,0)--(xpos,infinity)));
> iangle = direction (xpart itime) of wave[3];
> boatpos = (point (xpart itime) of wave[3]) shifted (-5,0); % shift to center horizontally

There was still an error that I introduced:
The boat on the first page is already way in, while on the last page it 
falls over the edge of the world.

I fixed several other things and drew a nicer boat. Feel free to use it.

Hraban