You learn to ram the whole weight of your body into an opponent to take it by surprise.
Benefit(s): With a successful Swim check, you can move half your speed as a move action or your full speed as a full-round action. You can run and charge underwater, though the maximum distance you can move while doing so is half the normal maximum distance. Further, while making a charge attack in water or on land, you can add twice your Strength bonus on the damage roll for your first unarmed strike on your turn.
Pathfinder Adventure Path #124: City in the Deep © 2017, Paizo Inc.; Authors: Amber E. Scott, with Alex Greenshields, Mikko Kallio, Mark Moreland, Tim Nightengale, and Kalervo Oikarinen.