Someone wasn't expecting that.

Finnick reacts instinctively, barely dodging the shots with a move that would have sent a land-bound combatant sprawling in the sand, but instead just looks kind of odd as he tumbles sideways through the air. With a wordless shout, he summons the powers of his trident, a waterspout gathering from the sea and then striking out at his foes with enormous force.

Given who he's trying to hit, it's a good thing his aim is a little off.