Must use anti-fog on lens to prevent fogging.
Mask fit is very important to prevent leakage Fit to your face, make sure that you get a good seal, nice and tight.
Proper adjustment of mask,mask strap postion and tension are crucial
Facial hair can sometimes be a problem to seal mask properly,
Beards are a problem because of the seal, they have a tendency to leak.
Hydrostatic pressure, both positive and negative and how it effects use the mask, Hydrostatic pressure, depending on the position of the counterlung and the divers position you can get high positive and negative pressure on the mask, which might cause it to leak
It is preferable to have a water trap between you and the scrubber, just in case of leaks
To use this type of equipment
You must have certification from a recognized certifying agency
In this type of equipment
ALSO
To use this type of equipment properly you should have a minimum of
25 hours on the specific type closed circuit rebreather that you are going to use, and
25 hours on the specific type of full face mask that you are going to use in open circuit mode.
