RE: [PSUBS-MAILIST] Compression Time Tables for Wet Exit

Brent,

Speak to Ray concerning video recordings of last year’s presentations.

Unless you have a bottom hatch to exit from, the increased air pressure you speak of will violently blow you out of the sub when the hatch is released. Most of those that have made escapes under emergency conditions have been knocked out as they are forced out of the hatch. If more than one person, only the first has made it.

Henderson use to make a zip-on exposure suit for the US Coast Guard. It would be almost impossible to get it on inside of a K-250 or 350. In an emergency situation, you are going to have problems getting out of the conning tower with a BC on as there are many opportunities for it to snag. In less it has an independent air supply attached to the vest, it will not inflate at depth on 1 or 2 CO₂ cartridges. You will find that 150 fsw is a LONG ways to swim up without fins (in an emergency, it is a long way with fins from personal experience).

For the 150 fsw scenario, a 40 ft³ aluminum cylinder is probably the best, it is compact yet has sufficient air to get you to the surface (from experience, a 16 ft³ pony bottle isn’t large enough). Undue the latches on the bubble hatch before beginning to internally flood the sub, don a scuba mask, place the regulator in your mouth and brace yourself down in the main portion of the hull (out of the conning tower), and start to fast flood the hull. When internal pressure is equalized, the hatch will be blown open and you shouldn’t be forced out. Now you are in control. With one hand over your head and one at your waist, exit the sub pushing the slender tank ahead of you. The one hand at your waist is there to help you get unsnagged if some item or clothing hangs on protrusion in the conning tower (if both were over head, you may not be able to get it back inside to untangle you). Now make your swimming ascent realizing without a depth gauge it is very difficult to tell if you are making progress towards the surface or sinking.

It should be an easy choice, your eardrums or your life…just reconcile yourself to a piercing headache. Oft times your eardrums will heal and I understand they can now be surgically repaired.

R/Jay

From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of Brent Hartwig
Sent: Sunday, July 06, 2008 8:13 PM
To: personal_submersibles@psubs.org
Subject: RE: [PSUBS-MAILIST] Compression Time Tables for Wet Exit

Hi Jay,

Thank you for the data. I would of liked to of heard your presentation. Perhaps someone video taped it?

If you need to do a wet exit and the water is not over say 150 fsw deep, then if you could have a specially customized multi piece zip on heavy wet suit to help deal with the cold and/or your in reasonably warm waters. Couldn't you compress up the sub with air from the HP air systems to match or closely match the external pressures before you let water in by opening a special large top vent and the normal flood valve, to get your body up to pressure without damaging your ear drums and stay dry longer? Then ascend with a weighted SCUBA tank and perhaps a BC, with normal decompression stops along the way using a laminated dive table, dive watch, dive lights? Of course as we know the best laid plans of mice and men. Having your ear drums broken, can't be good for your concentration in dealing with an emergency.

Regards,
Brent H