Rune harpoon

The rune harpoon is a tool used for harpooning fish in the Fishing skill and is capable of catching 100% more fish than a regular harpoon. It requires an Attack level of 50 to wield, but a Fishing level of 41 to use. The harpoon can be smithed using the Smithing skill at level 88 Smithing, using one rune bar on an anvil. The harpoon may also be gained as a drop from Celestial water warriors as an uncommon drop, but there's very high leveled requirements to fight these creatures.