Re: Need Beginner Equipment Help

On 14 Aug 2006 04:33:21 -0700, "-hh" <recscuba_google@xxxxxxxxxxxxxx>
wrote in rec.scuba:


John Hanson wrote:
"-hh" wrote:
John Hanson wrote:

September-October is going to give you the warmest lake
temps in the Great Lakes.

For the Northern Hemisphere, because of thermal lag, the warmest
temperatures are typically August into September. By October, things
are getting chilly.

Not what they tell me about Superior.

By any chance, are these are the same guys that said that a thermocline
of 35F water could exist below a 40F layer? :-)

It's true. I've witnessed it as has just about every other diver up
here as well. You don't account for underground streams and run off.
We have a river up north that actually disappears into the ground and
comes out God knows where into Superior. In the Spring, those water
temps are below 39 degrees and they come out somewhere below the
surface of the lake. Come up next June and I'll introduce you to
those cold waters below the surface.


Water temperatures are predicated by solar heating. Peak sunlight
occurs at the summer solstice - 21 June. Minimum sunlight occurs at
the winter solstice - 20/21 December.

Here's a good illustration of how lake waters typically respond. Sorry
I wasn't able to find one specifically for Lake Superior, but that's
your assignment:

Lake Superior is really an inland sea.


http://www.lrl.usace.army.mil/wc/wq/BRR.html

Water temperature vs. Month is the 2nd graph down on the right side.
The vertical dashed line is the "right now", which we can see herein
shows that we are "right now" (14 August) have just pased over the
annual statistical maximum.


If your sources tell you that Lake Superior is warmest at the Sept/Oct
(note: Fall Equinox = 21 Sept), because of the repetitive cycle of the
seasons, this would then have to mean that it would also have to be
coldest 6 months opposite, which would be at the (Sept+6 =
March)/(Oct+6 = April) timeframe (note: Spring Equinox = 21 March)

You are treating Superior as if it was some little lake like you have
down there in Texas. What you fail to realize is that warmer water is
constantly running off into it after about May and continues until
winter sets in. We don't get a lot of rain in November and when we do
get precipitation, it is usually snow and it doesn't readily run off
at that time of year. If it did, you'd see run off temps at
around33-35 degrees.



And "coldest" means "lake ice will be the thickest".

No, the water under the ice is always at a constant temperature of
around 40 degrees. You'd know that if you ever did and ice dive.


You've ice-fished enough to know that the ice isn't thickest in
March...that's when ice-out reporting starts in earnest.

You are making erroneous assumptions.



As a general rule of thumb, as soon as one does a warmwater dive, your
tolerance for freezing your ass off in coldwater just to see mud and
rocks will be significantly reduced.

The only part that gets cold on me is around my mask and my hands.
I don't think a drysuit will alleviate that. But, I do plan on getting
a drysuit. My point is one doesn't need it in the Great Lakes
although it is mandatory if one is going deep and doing deco stops.

Start your planning now for doing a Halloween dive in a Farmer John.
According to your buddies, the lake's water temperature should be just
past peak ;-)


The last day of October is considerable different than the first day.
But, some folks dive Superior every month of the year. Check this guy
out.
http://www.superiordivers.com/Images/Brads%20pics%20046.jpg
http://www.superiordivers.com/Madiera%20Set.htm
.

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