[droffel]

Harpoon guns are designed to do exactly that.

[pinkcan]

yea, let's equip boats that can't handle an orca with guns that shoot projectiles through meters of water

it's like trying to solve school shooting, by giving teachers guns

[dbish]

Sadly this seems to be an approach a large chunk of people actually want to try. Lots of folks out there who are not equipped to make suggestions

[someweirdperson]

Maximum depth of penetration is the ratio of the densities of the projectile and the matter to be penetrated times the length of the projectile. Harpoons have a higher density than water and are quite long, so they work.