How many of you don't use a "standard" octo?

[muddiver]

The MK V and a number of other free flow hats do not have a check valve in the air supply system. I take it you were diving the hat without the suit, therefore by reducing the pressure or air floe to the hat they could make it flood to a certain level, or so I suspect.

 

[Thalassamania]

That was it. Rather uncomfortable situation. They thought it was funny.

 

[Twistedarts]

Inflator octo here. tusa IR3

 

[Luis H]

The MK V and a number of other free flow hats do not have a check valve in the air supply system. I take it you were diving the hat without the suit, therefore by reducing the pressure or air floe to the hat they could make it flood to a certain level, or so I suspect.

I am almost positive that the Navy Mk-5 and most other recent hard hats do have a check valve in the system (they can just be added to the hose connection on any helmet). I think in the Mk-5 it is at the hose connection and I guess it is possible for someone to remove it, but that would be insane in the case of a hose failure or air supply failure. I will double check this…I could be wrong.

A few month ago I did have a partial flooding experience in a Mk-5, but we believe that it was a dress (the suit is called a dress ) leaked around my wrist. It was interesting how high the water was getting when I slowed down the air flow in so that I could hear the communications. When I increase the air flow the water would get pushed down again. My only concern was if I fell and ended up horizontally…the water would then get up in the helmet.

This thread has some pictures of that dive…this was just a fun dive:
http://www.scubaboard.com/forums/se...hat-divers-brownstone-quarry-connecticut.html

 

[Thalassamania]

I think it depends on just how the helmet is used. If it is mated to a watertight dress (chestplate, etc.) then a check valve is a must to keep you from being swuashed into the helmet if there were an air supply failure, if it is being used in shallow water with a jock and an open bottom, with the air being pumped through (as I was) then the check valve is (I was told) optional.

 

[muddiver]

A lot of the commercial dive schools use to have really old diving helmets for the students to use in the tanks or confined water dives under close supervision. The school I went to had an old Swendel free flow hat with no brest plat or a neck dam. We just kept it up right or you had to wait for it to clear if it got turned over and flooded. Also the DESCO pot did not come with a check valve until a couple of years ago.

 

[Thalassamania]

Ever use a push-pull system like a Piel Hat?

 

[muddiver]

Unh? A what? Pictures please.

 

[Thalassamania]

French hat with a flip visor, pumped habitat or PTC gas mix into the hat and sucked it out. We tested them for some government habitat programs ... kinda neat. I'll look for a photo.

Found it:

Great hat shots: http://offshorediver.com/divehats/compos.htm

 

[muddiver]

Looks like a copy of the Savoy hat.