This PrusaSlicer project cuts the original 3DBenchy.stl into parts, using 100% infill density for the aft hull and 10% lightning infill elsewhere. The resulting model floats upright when printed in PLA. This version is under 9 grams, but some of my previous test prints were over 12 grams and just barely floated, so there are many solutions to this problem.
I used PrusaSlicer 2.6 because its "center of gravity" visualization is somewhat useful.
The "Public Domain" license only applies to the slicer profile, as I didn't create the model.
You can see in the photo that the wall is just above the waterline. It stays in that orientation until you disturb it enough to spill water over the edge, at which point it capsizes.
Cool, how stable is it?
You can see in the photo that the wall is just above the waterline. It stays in that orientation until you disturb it enough to spill water over the edge, at which point it capsizes.