The thing is, that blue water looks so warm! The sun is so nice, the land is so nice, Tom Selleck always looked so nice swimming in it, that it’s a shock it isn’t very warm. I mean, you look at the water near San Francisco, it doesn’t look anything but cold and nasty, so it isn’t a surprise.
Then there are those who can’t get enough of cold water:
Honestly, stop being such a wimp! It’s invigorating and preserves the viability of your sperm for future generations of little Shagnastys. You want cold, try swimming in the North Sea! :eek:
Heh. When I was a little kiddy in Norway we’d go for a swim now and then during the summer.
Damn.
Find a little bit of sand on the shoreline somewhere and go for a swim in the beautiful clean clear water that sloped rapidly down to 50+ meters in depth.
Get out and lie in the sun every few minutes until the blue tinge went away and your teeth stopped chattering.
Nowadays I won’t go swimming unless it’s somewhere approximating to tropical. Having said that, I was very amused in the Maldives when the diving instructor was wearing a shorty ‘because it gets cold at this time of year’. I spent an hour at 20m wearing nothing but trunks and a thin t-shirt, luxuriating in the warmth. It really is a matter of what you are used to…
Why cold water? Because hypothermia is mood-altering!!! (I think endorphins are involved.)
Lake Michigan has been my swimming hole of choice, where the average water temperature year round is 39 degrees fahrenheit!
That’s because most of the water in the lake is deeper than 20 feet down, and the temperature of that water doesn’t change much. Only the thin surface water gets warmed up very much.
At the best of times, the August water by my shore may be 70-75 degrees, if the winds and currents have pushed the warm surface water in my direction. And that can change overnight, if the conditions change. I’ve enjoyed a pleasant swim one day in said 70 degree water, only to discover the very next day that the water temperature has dropped into the 40’s.
During our recent heat wave (temps in the upper 90’s) it was a challenge to cool off because Lake Michigan was in the 50’s in our area. But damn, once you got over the shock to the system, it was wonderful!
The water on the Nantucket Sound side of the Cape is about 10-15 degrees warmer than the water on the Brewster side. I realize that doesn’t help much, but it’s better than nothing 
Cold water doesn’t bother me once I’m in it; it’s the getting-into-it part that’s agony. I discovered there’s a reason why some people just jump in without thinking: The agony time is much, much shorter.