Did not see any 3D benchy whistles so created one with the inner side of a v29 made to fit with holes like anker chain holes on the benchy.

The original size is a bit small to blow so created a bigger version.

The open version has the box open so you can change pitch by putting your finger on it.

Prints without supports. You could add support enforcers on the outer openings of the bow. These have overhang. I printed mine without.

Recommend the big closed version. The smaller one has high pitch suitable for dog whistle I guess.