A speargun is a ranged underwater fishing device designed to launch a tethered spear or harpoon to impale fish or other marine animals and targets. Spearguns are used in sport fishing and underwater target shooting. The two basic types are pneumatic and elastic. Spear types come in a number of varieties including threaded, break-away and lined. Floats and buoys are common accessories when targeting larger fish.

A harpoon is a long spear-like projectile used in fishing, whaling, sealing, and other hunting activities to shoot, kill, and capture large fish or marine mammals such as seals, sea cows and whales. It accomplishes its task by impaling the target animal and securing it with barb or toggling claws, allowing the fishermen or hunters to use an attached rope or chain to pull and retrieve the animal. A harpoon can also be used as a ranged weapon against other watercraft in naval warfare.