Steel tanks dangerous?

[Remy B.]

Why you want to attempt to try to go up with a empty BCD ?

You mention this below

Tried to fin up, but barely able to maintain more than 1 minute when the BC is empty

a BCD should be nearly empty at the end of the dive with 1/3 of the gas or 500psi left in your tank.

don't understand correctly what are you trying to accomplish ? is it a BCD catastrophic failure scenario and how to be able to still go to surface ?

 

[Soloist]

FWIW perhaps a decade or so there was a well document set of deaths of two divers who were diving very negative doubles in open water whilst wearing wetsuits. While their BCDs could compensate for the weight of the gas at the surface, the BCDs could not compensate for the weight of the gas and the loss in wet suit buoyancy at depth. They went way down to Davey Jones locker and did not come back.

Understood, but this is the “Basic Scuba Discussions” forum and the OP is talking about diving a single HP120 steel NOT about diving doubles. I am concerned this thread, and others like it, will be blown out of proportion. Wasted energy.

 

[fisherdvm]

15 years ago I did dm training, and had to join the group to read and discuss. I got too much flaming for having “DM candidate “ as if it gave me more skills that I automatically should know. Only way to get rid of the label on SB is to join another group. And men who like to dive in pink panties was not an option- so solo sounds better!

 

[fisherdvm]

Dm nor instructor rating will not increase my IQ - but you certainly can help me logic out scenarios that are real - especially if one consider doubles or technical diving as a possibility in the future.

 

[Compressor]

Nah! @fisherdvm , this is a great thread! Just too scary a title, lol!

Agree. It was alarming to read.
I now read that the OP had issues with many things and it's good to go over the dive as he/she is doing.

Things happen and one needs to be able to analyze carefully to get to the root of the problem. Remember once I could not inflat wing: reason: the plastic attaching inflator hose to wing was completely off my wing. I felt like a dumb ass.

 

[fisherdvm]

Why you want to attempt to try to go up with a empty BCD ?

You mention this below

Tried to fin up, but barely able to maintain more than 1 minute when the BC is empty

a BCD should be nearly empty at the end of the dive with 1/3 of the gas or 500psi left in your tank.

don't understand correctly what are you trying to accomplish ? is it a BCD catastrophic failure scenario and how to be able to still go to surface ?

It is a simulation of a bcd failure and the worse case scenario sinking to hard bottom. Can a normal diver like myself- can he swim up with a full tank, full rig?

 

[fisherdvm]

It would not be the same finning at the surface- as the wetsuit would have more buoyancy. And the worse case scenario can not be tested.

 

[Soloist]

It would not be the same finning at the surface- as the wetsuit would have more buoyancy. And the worse case scenario can not be tested.

Sure it can. Start your dive at 110 feet, empty your BC and swim up to 80 feet. Test completed.

 

[DanielRJones]

It would not be the same finning at the surface- as the wetsuit would have more buoyancy. And the worse case scenario can not be tested.

You keep mentioning Steel tanks what is your issue with them. as you mentioned in your original post you had 4lb of ditchable lead that you did not dump.
12l faber steel is about -4kg at the start of a dive and 1kg negative at the end so
aluminium 80 is -2kg and +1kg at the end of a dive.

This is only a 4lb difference or 2kg in lead from the tank to the belt.

 

[fisherdvm]

You keep mentioning Steel tanks what is your issue with them. as you mentioned in your original post you had 4lb of ditchable lead that you did not dump.
12l faber steel is about -4kg at the start of a dive and 1kg negative at the end so
aluminium 80 is -2kg and +1kg at the end of a dive.

This is only a 4lb difference or 2kg in lead from the tank to the belt.

If I had an aluminum tank, let say an al 100. I would have about 12 lbs dichable weight at the surface. With the 120 hp steel, I would only have 4 lbs. Both would have about 10 lbs of negative force I would have to swim against at the surface with a full tank. This might not be a big burden for some... but for me and others it might be.