The Trench Knife is a straight upgrade from Nova's Shank. Like the shank, it deals out an average amount of damage per hit. The weapon strikes quickly, on par with the shank, with the relatively low damage being a minor problem due to being able to strike several times where a knife would only manage a single swing. However, the Trench Knife has better range.
The Switchblade released in the later Golden Grin Casino DLC has nearly the exact same stats as the Trench Knife, but with a faster unequip delay and an earlier unlock level, at 24, obsoleting the Trench Knife.
Special Operations Execution Kill 25 enemies while in stealth using the Trench knife. Unlocks the Red Bear mask, Short Barrel, Suppressed Barrel, Short Mag, Folded Stock, No Stock, Solid Stock, Heatsinked Suppressed Barrel for the Patchett L2A1 submachine gun, Barrel Sight 44, Damper.L 44 Nozzle for the Broomstick pistol, “Red Sun” material and “Death Dealer” pattern.