question for wildswimmer

[JET]

You advised me in a previous thread that thermometre watches weren't very good and fortunately I lost my bid on ebay for such a watch. I have now bought a pool thermometre. How long do you recomend I keep it in water for accurate reading and at what height should reading come from?

5/6 of us are being wimps and wearing wetsuits in sea now the brave one who isn't doesn't have a wetsuit. I am so bl---y hot in wetsuit feel confident can go down lots degrees before sea gets too cold. I know wetsuits are considered to be an advantage but mine makes me too buoyant and I prefer not to wear one.

[Wildswimmer]

How long do you recomend I keep it in water for accurate reading and at what height should reading come from?

30 seconds is usually enough, but anyway if you've got a pukka pool thermometer the bulb dips into a "bucket" which holds a sample of water. The accepted method for measuring the temperature of open water for swimming is to take a surface reading a couple of inches below the surface, then one at about 1 metre depth (a yard is near enough). The temperatures recorded on my water temp pages are surface measurements taken near the shore with a laboratory grade digital thermometer, but I also have records of deep water temperatures measured with my pool thermometer at surface and 1m. Anyone is welcome to the raw data when I eventually unload it off my vintage Psion palmtop.

Incidentally, I rarely bother with a 1m measurement in the sea, as the water is well mixed through wave action.

5/6 of us are being wimps and wearing wetsuits in sea now the brave one who isn't doesn't have a wetsuit. I am so bl---y hot in wetsuit feel confident can go down lots degrees before sea gets too cold. I know wetsuits are considered to be an advantage but mine makes me too buoyant and I prefer not to wear one.

I was sea swimming on Monday, bare-skin in water at 12.6C. I have a shorty wetsuit but have the same problems as you: overheating and excessive bouyancy.

The problem with these multi-purpose watches is that to get an accurate temperature reading you have to take the watch off and leave it for about 15 minutes. Otherwise you'll be measuring your skin temperature. Even in cold water this will be higher than ambient.

Wildswimmer Pete