What About Water Temperature?

Two weeks ago, the water temperature in the Gulf at Bradenton Beach was in the low 70’s. I had to use my dive-in, stand-up-fast, and dive-back-in approach to get into the water. But once I was in, it was ok. Right now, the water temperature in Lake Erie is in the mid 50’s. That’s too cold for me. When I swam in the Potomac River Swim, the water temperature was 65 degrees. I know I can swim 4 ½ hours in 65 degree water.  But back then my chocolate milkshake training regimen had built up some very nice natural insulation. Cholesterol issues have forced me to back off the milkshakes. Never-the-less, when Lake Erie gets up to 65 degrees, I’ll start thinking about swimming in it the lake.

 

If water temperature is too warm, swimmers lose their energy. If it is too cold, swimmers lose their heat. At the warm end of the range are public recreation swimming pools. These pools are intended for use by young children, seniors, and others people who don’t swim very far very fast. The pool managers try to keep these pools in the mid 80’s. The American Red Cross recommends 78 degrees for competition pools. Pools that are used exclusively for intense training may be kept at 73 degrees. 

 

Some open water swimmers wear wetsuits to protect against the cold. Wetsuit swimmers can overheat if the water temperature gets too high. I personally discourage the use of wetsuits if the water temperature is above 80 degrees.

Most open water swimmers will wear a silicone swim cap. They do this for two reasons. First, a brightly colored swim cap will make the swimmer more visible to boaters and jet-skiers. This enhances the safety of the swim. Second, a swim cap helps to retain heat. Since heat is lost through the head, a swim cap helps to slow down that heat loss. Some swimmers will wear two silicone swim caps – one over the other – to retain even more heat.  Other swimmers will wear a latex swim cap to accomplish the same thing. Latex swim caps are heavier and thicker than silicone swim caps. They inherently hold more heat.

Some swimmers experience discomfort in their ears if the water is too cold. They use wax ear plugs to eliminate that problem. Some swimmers will apply Vaseline to their chests to help retain heat there. If I was contemplating an English Channel swim, I would probably mention applying grease head-to-toe. But I’m not. So I won’t.

Every swimmer has his or her threshold for feeling the cold. Each open water swimmer has to determine his or her comfort level. Some trial and error is necessary. It’s like developing  one’s own personal heat index. Once that is known, appropriate heat retention strategies can be deployed.