Twins with only drysuit for buoyancy

[String]

We had to wear the gloves and hoods that we would normally wear here while doing it (5mm and 7mm respectively for me)
... man does that suit lose air fast when you do the neck seal

I tested mine in a pool, i cant dump through the neck seal. Combination of thick tight hood and thick gloves mean i cant get access to it. Not that it bothers me.

Water in your suit does not weigh anything in the water, it's the loss of lift that comes with a massive suit flood like zipper failure that is a problem, especially if it happens at the beginnig of a dive with full tank(s)

The issue isnt loss of lift - its loss of insulation. If you've got a long time left in the water that can be serious.

 

[D_B]

Good point about the cold water/insulation

What about the weight of non ditchable equipment and not wearing a BC of any kind? ... use a liftbag?

 

[jtivat]

We had to wear the gloves and hoods that we would normally wear here while doing it (5mm and 7mm respectively for me)
... man does that suit lose air fast when you do the neck seal

Water in your suit does not weigh anything in the water, it's the loss of lift that comes with a massive suit flood like zipper failure that is a problem, especially if it happens at the beginnig of a dive with full tank(s)

Water is your suit is a big issue in cold water with a deco hang to do!

 

[jtivat]

If people really think handling buoyancy in two devices is task loading then they need to re think diving in general. I have seen people with ten dives that can handle this.

 

[Lucy's Diver]

If people really think handling buoyancy in two devices is task loading then they need to re think diving in general. I have seen people with ten dives that can handle this.

So true. If you think you can't handle bouyancy with two devices you should not be diving with two devices. Its really not that hard.

 

[sambolino44]

If people really think handling buoyancy in two devices is task loading then they need to re think diving in general. I have seen people with ten dives that can handle this.

I wouldn't say that it isn't task loading, it's just that it's easy to do. Maybe some tasks are easier to handle than others, so they don't add up as much.

I keep just enough air in my suit to be comfortable and maintain neutral buoyancy with my buoyancy control device. If I try to keep my wing empty then the bubble in my suit gets so big that it burps out the neck seal if I get vertical.

When I ascend I have two things to let air out of instead of one, so I guess that's task loading, but it's easy to do, second nature really.

But the whole idea of task loading is that these little things add up; each one may be insignificant in itself, but it's another straw on the camel's back. If you are getting overloaded with tasks because of unanticipated problems - current faster than you thought, primary light went out, snagged on fishing line, and you just realized you forgot to add weight to compensate for the rented AL80 cylinder - you can't deny that having one less button to push is easier than two.

Nevertheless, I agree with you that divers should be able to manage two air pockets. And if you can't handle something easy like that, then there are probably a lot of other things you won't be able to handle, either.

 

[jtivat]

I wouldn't say that it isn't task loading, it's just that it's easy to do. Maybe some tasks are easier to handle than others, so they don't add up as much.

I keep just enough air in my suit to be comfortable and maintain neutral buoyancy with my buoyancy control device. If I try to keep my wing empty then the bubble in my suit gets so big that it burps out the neck seal if I get vertical.

When I ascend I have two things to let air out of instead of one, so I guess that's task loading, but it's easy to do, second nature really.

But the whole idea of task loading is that these little things add up; each one may be insignificant in itself, but it's another straw on the camel's back. If you are getting overloaded with tasks because of unanticipated problems - current faster than you thought, primary light went out, snagged on fishing line, and you just realized you forgot to add weight to compensate for the rented AL80 cylinder - you can't deny that having one less button to push is easier than two.

Nevertheless, I agree with you that divers should be able to manage two air pockets. And if you can't handle something easy like that, then there are probably a lot of other things you won't be able to handle, either.

Good points! I do realize that any new task underwater can be challenging that is why it is recommended to only add one new task at a time. After 10 to 20 dives with a dry suit the dealing with two air pockets should be second nature.

 

[Gene_Hobbs]

You might also find this article of interest:

Barsky SM, Heine JN. Observations on flooded dry suit buoyancy characteristics. In: Proceedings of the DCIEM Diver Thermal Protection Workshop, Defence and Civil Institute of Environmental Medicine, Toronto, CA, 31 Jan-2 Feb 1989. Edited by RY Nishi, Workshop Chairmen TT Romet and JA Sterba. RRR ID: 3922

Military and scientific divers have increasingly turned to dry suits for thermal protection in cold water and ice diving. Concurrent with this increase comes a concern for proper training procedures, underwear requirements, and safe configuration of the diving system. One area of common concern among all dry suit divers is the residual buoyancy available, or not available, in the event of a catastrophic dry suit failure. This issue must be considered due to the persistent use of dry suits as buoyancy compensators by many dry suit divers. This paper examines dry suit buoyancy under simulated failure conditions with a variety of suit/underwear combinations. Of the 13 combinations tested, after complete flooding and removal of the diver's lead weights, 2 systems remained positively buoyant while the other systems eventually all became negatively buoyant. Recommendations are given for equipment requirements, training, and emergency procedures for dry suit usage.