Pros & Cons of Using a Full Face Mask

[k-valve]

Can be more expensive too...on one of your other threads, the Switchbock was talked about, they range from $300-500...expensive option to keep the FFM on(for gas sharing), but can be a necessity....our PSD teams use them for the pony bottles

I do some deco diving with up to two additional gases. Never really thought about using the FFM with it. Can you tell me some more about the Switchbock or where I can find more information about it? Thanks!

 

[Dive Right In Scuba]

Sartek RSV-1

THis is the one we supply our Public Safety Divers with:

Sartek Industries, Inc. RSV-1 Redundant Supply Valve

 

[DA Aquamaster]

I use an M&J industries gas block purchased from Oxycheq.

I noticed they have gotten cheaper ($299) and now come in left and right hand versions. If they are still the same valve they are well made and smoothly operating pieces of gear.

fittings

It is about 3/4 of the way down the page and the picture is above the text.

 

[k-valve]

Additional Con: If you go OOG, it seems like a giant cluster. Although, I don't know this for sure since I have never used one.

Yeah, it does...but when wouldn't it be a cluster if you found yourself in an out of gas situation?

I think (not sure...just speculating), based on what I've been told today you have a couple of options. Carry a spare mask and use it when you switch to your alternate, or install a switch block (see RJack's post) in which case the diver switches gases without removing the mask. The switch block doesn't sound like it'll help much if you have a failure anywhere at the mask/reg end though.

After reading all the comments today I'm beginning to feel like a "regular" mask is the best option unless you require communications or full face protection.

 

[texdiveguy]

After reading all the comments today I'm beginning to feel like a "regular" mask is the best option unless you require communications or full face protection.

IMO- you summed it up nicely!

 

[OTS Comms]

There are three benefits commonly associated with FFMs:

1. Required for underwater communications
2. Environmental Protection - cold or contaminated water
3. Physiological - less jaw fatigue; allows inspired gas to be warmed and moistened by breathing through your nose

As with anything, these benefits come at a cost.

1. Slightly higher CO2 retention -- for most divers this is a non-issue.
2. Slightly different diving procedures than taught in O/W courses -- donning/doffing, mask clear, OOA, equalizing
3. More expensive -- although we are working to make the price more palatable for sport divers, you should weigh the value of voice communications with your buddy, other divers in the water (as far away as 6km), as well as topside; the type of environment you typically in, and the added comfort afforded by a FFM with the incremental cost of an FFM.

FFMs are probably not for everyone, but I would also add that you shouldn't let your experience with one or two manufacturer's FFMs sour you to the entire idea. As with many products in the SCUBA industry, there are significant differences between designs -- some good, some bad.

Craig

 

[shotthebreeze]

Mask clearing could also be an issue for some...

 

[rjack321]

Yeah, it does...but when wouldn't it be a cluster if you found yourself in an out of gas situation?

A normal 2nd stage with a generic (not the moulded to your teeth style) mouthpiece on a 5 to 7ft hose makes gas donation casual.

And since this is the Tech diving forum I would postulate that this configuration with proper training is used by the vast majority of deco and overhead divers today. If you can't donate freely and easily you should not be diving an environment where the surface is not directly accessible (due to a real or virtual overhead).

A FFM is warrented for:
contaminated water
when comms are required
for in water recompression due to the long O2 exposures and potential to tox.

For "normal" deco, cave, and wreck diving a FFM is not the choice of 99.9% of these divers. Its too complex and presents additional hazards that outweigh the benefits.

 

[jumbo]

I have a neptune ffm, and I dont dive with it unless conditions warrent it I.E. rotten water.

Once the new, cool factor wore off, I quit wearing it for rec, dives. In fact ill give you a good deal on one if you want

JUMBO

 

[k-valve]

A normal 2nd stage with a generic (not the moulded to your teeth style) mouthpiece on a 5 to 7ft hose makes gas donation casual.

My point was that you shouldn't find yourself in an out of air situation in the first place. We can start arguing the virtues of the long hose and the best way to share air in a different thread if you'd like. BTW, you're preaching to the choir, as what you describe is the exact configuration I dive.

Let's not jump into the DIR/non-DIR BS here. I'm just looking for pros and cons of the FFM.