Cold Water Shaping


Why you need to take water temp into consideration when shaping and why volume is your new best friend in colder climates.


1. Cold water requires a wetsuit; and if the water is cold enough a pretty thick suit. This additional wetsuit weight can make paddling a workout and let's face it, most of us surf so we don't have to lift weights.

Volume just became your new best friend.

Suggestion: If you are shaping PU (polyurethane foam), do your best to hide up to an extra 1/4" of foam in your thickness calculation; or leave your normal thickness but shape EPS. If you are shaping EPS (expanded polystyrene foam), just add an extra 1/8" to your thickness and an extra 1/8" of width to your cool water board.

Disclaimer: Regardless of water temperature, if you are going to be surfing windy or stormy conditions, try and stay away from an EPS core. The PU core will handle a sloppy wave face with more confidence by not responding to every bit of texture like EPS will.



2. The affect of water temperature on buoyancy is another hot topic that I really had to research; and research carefully because there is a lot of non-scientific information floating around the web, no pun intended. Here are my findings...

Warm water has a lower density than cold water, thus warm water will always float on top of cold water. Think of warm water being "lighter" or weighing less and floating and cold water being "heavier" or weighing more and sinking. Now let's throw an object into the mix.

A surfer on a surfboard will float in all temperatures of water, but the two questions are (1) will you float more or less in cold water, and (2) would changing the volume of the surfboard affect the buoyancy.

The buoyancy of a floating object (surfboard) is measured by the volume of water it displaces. In warm water (less dense), a surfboard has the ability to sit lower in the water because the water is easier to displace. In cold water (more dense), a surfboard displaces less water and therefore sits higher in the water.