Skishing is a mix of skiing and fishing. The idea is to hook a fish big enough to tow the angler through the water.
Without the benefit of a boat or land, the fight is considered to be, by the fisherman anyway, on more equal terms. Skishers swim sometimes hundreds of yards from shore to water well over their head, with their flippers and the buoyancy of their wetsuits keeping them afloat.
LINK (Via: The Wall St Journal)