Minnesota Sump diving

[John Ackerman]

We have some sumps that are waiting to be pushed in SE Minnesota! Good chance that major dry cave segments can be discovered via the sumps. For more information you can contact me at cavepreserve@gmail.com John Ackerman

[Squirrel Girl]

I would totally be all over that........ if you stick a big @$$ immersion heater in the water upstream! :-p

[FW]

I would totally be all over that........ if you stick a big @$$ immersion heater in the water upstream! :-p

You can always put the heater in your drysuit

[Squirrel Girl]

You can always put the heater in your drysuit

It's not my drysuit that's the problem. It's my hands and face that are worse.

[FW]

It's not my drysuit that's the problem. It's my hands and face that are worse.

Dry Gloves, and this: http://www.stingguard.com/thermal_pr...old_water.html

[Duncan Price]

Notwithstanding the interestes of our cousins from OFC* then I would be keen to do this. The water will be plenty warm enough. The only issue is getting cylinders (and lead) locally. The rest of the kit we can fly in with. I have already discussed with Forrest the possibility of a CDG sump diving expedition to OFC at some point. John will be hearing from me in due course.

* Our Former Colonies

[JE]

It is interesting to note:

During 6 months of diving in Lake Superior, even under the ice, the water temperature rarely drops below 37f. {I lived & worked in northern Wisconsin}{I dove almost every day from mid March to the end of September}

In Summit & Pitkin counties, Colorado, I never found the water temperatures to drop below 37f even in the dead of winter{below the ice or thermoclines}even when it was below zero! Including a recovery dive for the Sheriff's office at 7,800' from the Ruedi Reservoir in mid November during a snow storm ! {drunk drove thru a barrier fence into the Reservoir}{240' deep.....commercial dive team from Denver recovered the victim & vehicle}
Ruedi Reservoir
White River National Forest, Colorado 81621

My point being; dry or wet suit, your body adapts & the initial dunking is the only time that you feel the cold. In a matter of minutes, your body will warm & you nose or lips will be the only parts that really suffer.

We are spoiled by the warm spring waters of Florida . We should travel north or west to appreciate what we have in the South !

[DA Aquamaster]

It is interesting to note:

During 6 months of diving in Lake Superior, even under the ice, the water temperature rarely drops below 37f. {I lived & worked in northern Wisconsin}{I dove almost every day from mid March to the end of September}!

Water begins to expand and becomes slightly more buoyant at 35 degrees. That's one of those odds things critical to life on the planet as it means ice then forms at the surface of bodies of water.

If it did not, and ice formed at the bottom of lakes, the water above would insulate it, with ice then remaining on the bottom of deep bodies of water year round, slowly accumulating over time. If that occurred, over a period of a few years, lakes would freeze all the way to the surface, and the the combined climatic effects would turn us into a giant ice ball.

That expansion also drives the seasonal turnover of lakes, carrying oxygen throughout the water column on shallower lakes and taking more oxygen to deeper depths in deeper bodies of water.

Consequently, given this expansion of water, the colder water in the winter is normally at or near the surface with comparatively warmer water at the bottom. Dive computers are still cooling or warming to ambient when the diver passes through the shallow layer of 35-32 degree water, so divers seldom notice it. In that regard when diving in the frozen north in deep bodies of water I usually saw bottom temps of 37-39 degrees F varying a couple degrees from summer to winter.

[FW]

Notwithstanding the interestes of our cousins from OFC* then I would be keen to do this. The water will be plenty warm enough. The only issue is getting cylinders (and lead) locally. The rest of the kit we can fly in with. I have already discussed with Forrest the possibility of a CDG sump diving expedition to OFC at some point. John will be hearing from me in due course.

* Our Former Colonies

If you are willing to use Aluminium 80s, then they would be easy to get, as well as lead. Steel tanks may be possible, but would take more lead time to sort. Let me know, I may join you.

[rjack]

When is this scheduled? I am no sump expert (or expert at anything really) but have family in the Twin Cities and could justify a trip which includes some diving.