I wouldn't considering how many assholes the fecal matter on those bills came from. (of all commonly handled items in day to day life, cash tends to have the highest % of fecal matter, and oddly enough highest % of cocaine residue in the mainstream).
So if I ever say "keep the change", its not cuz I'm being generous, I just don't want your shit on me.
If you really want to sail around, a big catamaran has way more interior space than a regular sailboat, and is faster (if you don't overload it) and is more stable (less side to side motion, less rocking).