Full face masks for cold water diving

[mndiver]

Other Chris,  good info on the FFM.  Do you really find yourself concerned about the microorganisms in water?   There is no doubt they are there, but other than somebody asking how I could swim in Lake Michigan after the MMSD did a raw sewage dump, it isn't something I hear people talk much about.   Maybe because we don't have coms in our masks ;D

How are air shares and gas switches handled with a FFM?

Microorganisms?  Well yes I do think about them, I don’t necessarily worry about them.  When I dive the Great Lakes I don’t give it a thought.  When I dive the smaller local ponds and lakes I do worry about it.  Here in the twin cities we had several lakes closed in past years for microorganism outbreaks leading to sick kids.  They are fueled by warm water combined with goose/duck poop.  I was diving one of them the day before it was closed.  It mostly impacts the shallow areas as you enter and exit the lake.  I also dig around the bottom quite a bit and there are loads of farm run off fueled microorganisms there.  I know lots of “muck” diver that have “just not felt right” or had the “runs” the day after a dive.  I am now aware of the potential risk and take appropriate measures.  Cleaning your gear after every dive in a disinfectant is a great idea too. I use Simple Green D.

Air Shares?  Well, you don’t.  You can donate your safe second or a redundant air supply, but if you take the FFM off, you can’t breath or see.  I carry a regular dive mask in a pocket just in case. 

A positive pressure FFM will vent air out if it gets a hole in it.  You hear the bubbles and abort the dive.  If you have a free flow, you just abort the dive, the AGA vents the excess air and other than the noise, you don’t notice it much.  If you get a non-positive pressure mask, then you can pull air into the mask when you breath, but since it is such a large volume mask with the visor, you can typically move any water in the mask to the exhaust and purge it out.  If the positive pressure AGA fails, it fails open and it is handled just like a free flow. 

Gas switching.  You have several options here.  You can attach a gas block from Sartek, Kirby Morgan, or MJ Enterprises and just flip a switch when you want to change gas.  You can even add a LOCKING high volume quick disconnect designed for breathing gas.  You can put one on each of your tanks and just plug and play when you want to switch gas.  The Sartek attaches to the AGA FFM, the others attach to a harness strap. 

Yes, save your pennies for a long time.  The last AGA I got was over $1600 with com gear and an ambient breathing valve installed.  You can skip com and save several hundred dollars.  I think the AGA with ABV and a hose is about $1100.

Later,

Chris O: AKA MNDiver