Water temps at Walden

[glad]

Water temperatures are still pretty chilly at Walden; in the low 60's. I swam (not with a boat) with a full wet suit this evening and it was still a bit of a challenge.

Sad but true the water still requires one to continue to dress accordingly.

[djlewis]

Interesting... lakes are really different re water temps. I measured Mystic late last week, and it was a comfy (but still wet-suitable) 67-68. Given air temps since then, I imagine it's still about there, maybe even closer to 70 by now.

So, for anyone coming to the Mystic practice session tonight, I do recommend a wet suit, especially since we will be doing some immersion. But it should be pretty comfortable.

Oh yes -- please no cotton clothing on the water in any case. That's a quick way to turn a warm-ish day into a frigid one.

Lastly, if anyone is worrried about pollution after the rainstorm of Saturday, me experiene watching pollution levels closely a couple of years ago leads me to believe that it will be fine. Three days largely without rain and with substantial sun is more than enough to cleanse the lake under normal circumstances. But the season's official monitoring at nearby Sandy Beach has not yet begun, so we can't be 100% sure.

--David.

[glad]

Though I am not scientifically certain, I think Walden is more cold because it is deeper, more spring fed and has less particulate to absorb the sun's heat.

[djlewis]

>Though I am not scientifically certain, I think Walden is

>more cold because it is deeper, more spring fed and has less

>particulate to absorb the sun's heat.

Sounds pretty scientific to me ;-))) And correct. The Mystic Lakes are really just a bulge in the Aberjona-Mystic River system. Obviously, Upper Mystic is formed partially by the dam between the Lakes, but Lower seems entirely natural.

Hmmm... without the dam, I bet there'd be a stretch of whitewater somewhere in there.

--David.

[Sanjay]

Walden is a "kettle pond," created in the last glacial retreat, and is really deep--about 80 feet, according to Thoreau. It takes its time warming up in the spring, but then stays warm later in the fall than the shallower lakes such as Mystic and Cochituate.

The rivers tend to warm the fastest, since they drain water off warmed land. The lower Charles is positively balmy now even as Walden stays cold.

Sanjay

[rcohn]

Walden is actually just over 100 ft deep and the thermocline is quite dramatic. Two of us used Walden regularly to practice freediving a few years ago. Even in the warmest months the water is quite cold below 20 ft, not to mention datk. John, who was working on deep freediving (unlike me) made to the bottom at around a 95 ft depth.

This year we began regular kayak practice there at the beginning of April when the boat ramp opened. The water last Sunday felt quite balmy compared to the first few weeks

Ralph Cohn

White SOF

Elaho DS, blue & white with yellow trim

[JohnHuth]

I was at the Hopkinton Resevoir last weekend, and it was quite warm. I wore a wetsuit, but could've easily gotten away with swim trunks and a light polypro top (and I was in the water a lot - practicing reentry-and-rolls, among other things). (I also tend to be pretty warm-blooded, however)

Hopkington is pretty shallow.

[djlewis]

Forgot to report from the Mystic Lakes skills session on Tuesday -- the water temp was ~down~ to 62-3, form 67-8 five days before. I assume the drop was due to the cooler air temps and the rain.

--David.