This Trident is a House relic of the Dre'lin family. The Dre'lin were a prominent sea elf family that were decimated when a deal with dragon turtles went bad leading to the destruction of their palace and all inside. The rubble was looted and this Trident was passed from hand to hand as their owners had no clue as to the powerful current that passed through and around the Trident.
Once a day you may shoot a bolt of lightning forming a line 100 feet long and 5 feet wide out from your Trident in a direction you choose. Each creature in the line must make a Dexterity saving throw. A creature takes 8D6 lightning damage on a failed save, or half as much damage on a successful one. Every creature (including you) within 10 feet of the bolt must roll a Constitution saving throw DC 12 and on a fail takes 1D4 lightning damage.
Electrical attacks in salt water.... Shocking. (Sad rimshot)