Another water pressure question

[Remy B.]

Simple answer, if you are not in a mountain then go get that item, just don't fall from 120ft in the hole, and take your training manuals and read them again when you have time.

 

[halocline]

Trying to get a simple answer to real world problem.

Person drops item down hole and needs to retrieve it. Hole is 120 feet down until you hit water. Water depth is approximately 60 feet.

Is texas the real world? I don't know and I've lived there for 20 years.

Probably need way more information about the environment to make any reasonably helpful comment other than, the 60 ft depth is not any different than 60 ft from level flat ground, approximately 3 times surface air pressure. If its nice clear water with a hard bottom and it won't take much time to find your object, it's a dive I could easily do on a very small tank. That would make carrying things back a little easier.

Good luck!

 

[Akimbo]

Something is amiss; I just looked at erakor’s profile. Could this be correct???

Certification Agencies:
PADI, NAUI, SSI
# of Logged Dives:
5,000 - ∞
Dive Classification:
Instructor / Assistant Instructor / Dive Master / Dive Con
Years Certified:
Ten Or More Years

 

[Texasguy]

Well, if it is night time, a person would need a really good lighting system.

Even during a day a 60 foot hole can be very dark.

 

[erakor]

Thanks for the responses...this is exactly as I thought but after reading a few of these water pressure threads and seeing a myriad of conflicting answers based on hypothetical parameters I thought I would just ask the question in as simplest terms possible to confirm what before reading some of the threads I knew to be true. That the 120 foot drop to the water would not have a significant influence on the approx 60 foot dive in regards to pressure, depth calculations etc..... Thanks again.

Really glad I found this board.

 

[Subcooled]

One foot of water is one thousand feet of air. This is a lead and feathers issue.

Things only get complicated at high elevantion (mountains) where you are supersaturated and offgassing (because of the obvious ascent after a lifetime on the bottom).

There is one thing to notice though: Breathing pressurized gas and then performing a 120 feet (rope?) climb is not the best combination ever imagined. Keep the dive short. Use rich nitrox. Enjoy some oxygen. Float around and have a nap Only the climb.

---------- Post added April 29th, 2015 at 12:07 PM ----------

Oh, thanks Akimbo. Didn't notice the profile.
New try.

This is a rope access issue. You will need an SRT harness, a Petzl stop or equivalent, a breaking carabiner, cowstails, and ascenders, and some skill to use those. Someone also needs to rig the pitch. In addition you need some gear to winch down the cylinders. Sidemount and haul sacks would be optimal, but I have heard how rebreathers have been sent down a pitch... At the surface you need to detach from the rope, leave extra dangling climbing gear there (this is the annoying part), and attach cylinders. Do the dive, and reverse. The caveats of my previous post still apply.

Hint: locate a sump diver. Maybe you buy a beer for these local guys: National Speleological Society Cave Diving Section