What is the "right" clothing to be wearing while on the water?
Many folks make the mistake of heading out paddling on cold water only dressed for the temperature of the air and not the water. Did you know that the water temperature in the Bay of Fundy Rarely goes above 15 degrees C/59 degrees Fahrenheit? Did you know that the University of Manitoba (which Canadian Coast Guard and Transport Canada gleans much of their cold water research) describes 15 degrees as the threshold for cold water shock?
How can we defend against this? To start with we can wear the proper thermal protection which consists of:
- No Cotton - Cotton is great for workout gear as it is made up of hollow fibers that fill with water. These water saturated fibers rest against your skin which cools your core through conduction and as the water evaporates it pulls heat from your body to fuel the water's change of state from a liquid to a gas as it evaporates. Water can draw off heat from your body 20 times faster than the air!
- Base Layer (BL) - The base layer should be a non-cotton blend that will wick water away from your skin. The base layer (when used with a drysuit) will provide your base thermal insulation value so make sure it is adequate for the water temperature. Many folks prefer a Polar Fleece, Polyester, Polypropylene, Merino Wool, wool blend (make sure no cotton) and Bamboo (make sure no cotton blended). Any synthetic blend is better than cotton. If using a wetsuit it is best for the wetsuit to be against your skin as much as possible. Wetsuits are designed to hold a small amount of water against your skin and preventing that water layer from being moved. Wetsuits have nitrogen bubbles trapped within the material that help to provide insulation value in conjunction with the trapped water. The trapped water is heated by the body and held in place keeping the wearer relatively warm in cold water. There are evaporative losses associated with wetsuits (this can be felt when the wearer gets out of the water into the wind) but these loses are minimal in comparison to wet cotton clothes in the wind. If wearing a wetsuit during cold water paddling additional layers should be worn outside the wetsuit or farmer john. The wetsuit will be in case of immersion, the outer layers will keep you warm while paddling.
- Mid Layer (ML) - The mid layer, again, wants to be cotton free. Popular mid layer materials are Polar Fleece, Merino wool, Polyester, Polypropylene, Bambo (make sure no cotton blended) and Wool Blend (make sure no cotton blended). The mid layer (when used with a drysuit will provide the bulk of your thermal protection from convection and conduction) it's thickness will be dependent on the water temperature. The mid layer should have good moisture wicking properties and look for anti-microbial/bacterial properties where available. When used in conjunction with a wetsuit, your mid layer will provide thermal protection from the air temperature in conjunction with some sort of wind breaker.
- Outer Layer (OL) - The outer layer will either keep your thermal layers dry and prevent wind from robbing you of heat through convection (Drysuit) or in the case of a wetsuit your wind breaker or drytop will keep the wind from blowing through your layers. In the case of the drysuit, this is the most important part of your thermal protection. When faced with prolonged immersion (for you folks that have never even tried to get back in you canoe or kayak) a drysuit in conjunction with proper thermal layers will keep you comfortable the longest.