Surf Ski - Construction and Design

Construction and Design

Some cheaper, heavier surf skis are made from polyethylene. Light weight surf skis are made of composite layers of epoxy or polyester resin-bonded cloth: fibreglass, kevlar, carbon fibre or a mixture. To cut weight, the number of layers of the material and the amount of resin may be minimised to just that necessary for structural integrity or increased for extra strength and durability in heavy surf.

Early surf skis were constructed in the same way as early surfboards, being laminated from light wood and sometimes covered with fabric. In the 1960s, the first foam surfboards and surf skis were carved from a single block of expanded polystyrene foam, strengthened with wooden stringers and covered with a thin layer of fibreglass. As the demand for surf skis grew in the 1970s, this custom method of production proved too costly and moulds were made from the most successful surf skis so that moulded craft could be made more cost effectively out of glass-fibre. At the same time, there was a divergence in ski design, one type becoming known as the lifesaving specification surf ski (spec ski) and the other being the long distance or ocean racing surf ski.

Ocean racing surf skis differ from spec skis in that they are longer, have sharply pointed bows and under stern rudders. The front of the modern lifesaving type surf ski is often flared to prevent nose diving on returning to shore when surfing down large steep waves. Ocean racing surf skis are also usually longer than long distance racing kayaks; they have more longitudinal curvature (rocker); they typically have less transverse primary and secondary stability but more longitudinal stability because the paddler is seated more towards the centre of the craft to enhance wave riding ability. An ocean racing surf ski must have enough volume in the bow to provide buoyancy when punching through surf, a long waterline to make use of ocean swells, a sleek, narrow shape to reduce water resistance, as well as enough stability to make paddling in rough conditions feasible.