The spec ski is the traditional craft used by surf life saving clubs and must adhere to strict size and weight. ... The Spec ski is designed tougher and with more rocker to manoeuvre in and out of the wave zone. The ocean ski is made for long-distance ocean paddling and is usually raced downwind with the swells.
There are two main varieties of surf ski – traditional spec skis and ocean skis. Traditional spec skis are used by Surf Life Saving Clubs. They're built to a standard size and weight, and are designed to negotiate the surf zone. Ocean skis on the other hand are designed for long distance paddling, and are normally raced downwind on ocean swells.