hat tip @Swordsmyth

I'm not pulling a @Danke but, seriously, I already got one.

Back in the day when hunting, literally, swordfish from a bow pulpit could be a way to make money commercial fishing, this was what you used, exactly as Quint showed you in Jaws. Or you could use a "flying gaff".

Haven't shot it 30 years now, but I got one.

Have one these as well:

That's a 45-70 single shot line throwing gun.

A blank cartridge propelled one of the bass rods which was attached to thin twine, that was held in the aluminum drum under the barrel.

That was attached to a 3/4 inch manila or poly-d line, which that was attached to a tow wire which was sometimes attached to tow chain.

The idea was you could shoot over a tow line to a vessel in distress, or from you if needed, to another vessel that could not get close enough to safely pass a line, due to weather or rocks and shoals or what have you.

Nowadays we use rockets: