Minimum fuel

"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote in message
news:JOGdneSVwODlZTbZnZ2dnUVZ_rmdnZ2d@wideopenwest .com...
What's the water temperature in Lake Erie this time of year? :-(

Surface temperature is about 70 degrees F...

Wow. When I read that I was skeptical. But, not only are you correct
(duh), you were even being a bit conservative:

http://www.wbuf.noaa.gov/laketemps/laketemps.htm

Even 30 feet below the surface, the measured temperature is 73F. On the
surface, it may be quite a bit warmer than that.

Looking here (the minimum temperatures over the last 80 years):
http://www.wbuf.noaa.gov/laketemps/COLD_LE.htm

I am amazed at the variation in temperature of the lake during the year, and
just how warm the *lowest* temperatures on record are during the summer.
I'm so used to our snow-melt-fed lakes here in the Puget Sound area that I
forgot many inland lakes can get quite warm during the summer (for example,
at that same depth of 30 feet, Lake Sammamish varies only within a range of
about 15F throughout the year, peaking about about 60-65F...even at the very
surface, it rarely gets as high as 70F, and even then only briefly right
near the end of the summer).

The water at the Lake Erie beaches must feel like bathwater! (in the
summer, I mean)

Pete

"Peter Duniho" wrote:
http://www.wbuf.noaa.gov/laketemps/COLD_LE.htm


The water at the Lake Erie beaches must feel like bathwater! (in the
summer, I mean)

Surfers wear wetsuits in 70 deg. water. It's cold enough to produce
hypothermia in 6-12 hours of exposure.

--
Dan
C172RG at BFM

Lake Erie depth charts

http://www.ngdc.noaa.gov/mgg/greatla.../e_gmorph.htm#
a789

"Dan Luke" wrote in message
...

"Peter Duniho" wrote:
http://www.wbuf.noaa.gov/laketemps/COLD_LE.htm


The water at the Lake Erie beaches must feel like bathwater! (in the
summer, I mean)

Surfers wear wetsuits in 70 deg. water. It's cold enough to produce
hypothermia in 6-12 hours of exposure.

Something has gotten lost in the translation, I think.

The water temp of 70 degrees is at 30 feet of depth. At the surface, it is
much warmer. It does indeed get very warm at the surface, at the beaches.
--
Jim in NC

Morgans wrote:
Surfers wear wetsuits in 70 deg. water. It's cold enough to produce
hypothermia in 6-12 hours of exposure.

Something has gotten lost in the translation, I think.

The water temp of 70 degrees is at 30 feet of depth. At the surface, it is
much warmer. It does indeed get very warm at the surface, at the beaches.


Surface water is probably much warmer but any water less than body temperature
will eventually draw off heat. Back in my young and stupid days, I used to
scuba dive in rock quarries. The surface temp would typically be about 80-85
degrees in the summer, quite comfortable in just a swimsuit. Once you dropped
below the thermocline, the water temperature would drop a good 35 degrees in the
span of just a couple of feet's worth of depth. 45 degree water is damned cold
even in a wetsuit with full hood and gloves. 85 degrees is damned hot in a
wetsuit with full hood and gloves.

Thermoclines in those quarries were usually in the 15-25 foot range in the
summertime. Of course in the winter, there is no thermocline... it's cold from
top to bottom.

Water temps in the ocean off the NC coast are similar at the surface but they
don't have a thermocline until maybe 80 feet or so. Even then the temp doesn't
drop more than maybe 10 degrees or so.

70 degree water is rather bracing but feels good when the air is hot and humid.
However, you can't handle it for more than an hour or so without getting
chilled.

Now, how far were they going to have to swim in Lake Erie?



--
Mortimer Schnerd, RN

VE

"Mortimer Schnerd, RN" wrote in message
m...
[...]
Now, how far were they going to have to swim in Lake Erie?

Depends on where they crash. But even if they swam 30 feet below the
surface, in the 70 degree water, according to Dan they'd have 6-12 hours to
get wherever they were going.

I don't know about you, but *I* can't hold my breath that long.

"Mortimer Schnerd, RN" wrote:

Surface water is probably much warmer but any water less than body
temperature will eventually draw off heat.

The rule I learned was 50/50/50 -- 50 minutes in 50 degree water means a
50% chance of survival.