2 recent deaths where snorkelers happened to be using full face masks

[tridacna]

No air from your mouth or nose enters the face cavity. No moisture-laden means no fogging. The mouth/nose cavity fogs up quickly -you can see it immediately but is irrelevant.

Air is delivered and recycled through tubes on each side of the mask then up to the snorkel. Air in the eye cavity remains undisturbed.

Once you try one, it becomes quite obvious. $50 does not get you the “right” one either. They usually run about $99. Not worth cheaping out here.

 

[dmaziuk]

I've been on a snorkel boat once. Everyone grabbed masks/fins/snorkels from a bin and jumped in.

Last time we rented masks & snorkels, that was about as much instruction as we got too. OTOH I was never given an e.g. "how to kayak" lecture when renting a kayak either.

 

[John C. Ratliff]

No all. Some of the YouTube images also show fogging. I use one in the shop with a powered respirator to protect from fine dust. It does fog until I hook up the hose from the back-mounted filter and fan. Mine is comfortable on me, as FFMs go. Picked it up for $30.



Very dependent on the fit.

Akimbo,

What you were wearing was a "powered air purifying respirator," which is a whole different "critter" than a full face snorkel mask. I'll say more about the latter later.

SeaRat

 

[Akimbo]

What you were wearing was a "powered air purifying respirator," which is a whole different "critter" than a full face snorkel mask. I'll say more about the latter later.

No question. The point was the snorkel mask that was modified to use in the shop did fog until the powered ventilator was connected. The fit of the oral-nasal on this mask is actually pretty good on me, a lot better than on most commercial diving masks and hats. It also fit a great deal better than the mask that came with it and is a lot less delicate.

To be fair, this modified shop rig works well on the north coast of California but it would be pretty uncomfortable in warm climates.

 

[eelpout]

I am curious then with this feature "No air from your mouth or nose enters the face cavity" How does one equalize pressure in the face cavity? So the mask is exclusively designed for surface use only?

 

[kelemvor]

No air from your mouth or nose enters the face cavity. No moisture-laden means no fogging. The mouth/nose cavity fogs up quickly -you can see it immediately but is irrelevant.

Air is delivered and recycled through tubes on each side of the mask then up to the snorkel. Air in the eye cavity remains undisturbed.

Once you try one, it becomes quite obvious. $50 does not get you the “right” one either. They usually run about $99. Not worth cheaping out here.

How does the end result differ from a regular mask with regards to fogging in that case?

 

[Akimbo]

So the mask is exclusively designed for surface use only?

For all practical purposes, yes.

 

[tridacna]

How does the end result differ from a regular mask with regards to fogging in that case?

In a regular mask, you will involuntarily exhale air through your nose. It's part of the same cavity. The warm moist air hits the cold surface and voila!

In the FFM, no air is introduced. Just try it some time. Seeing the mouth nose "lens" fog up is quite an "aha" moment.

 

[kelemvor]

In a regular mask, you will involuntarily exhale air through your nose. It's part of the same cavity. The warm moist air hits the cold surface and voila!

In the FFM, no air is introduced. Just try it some time. Seeing the mouth nose "lens" fog up is quite an "aha" moment.

I see, I didn't realize that the eye and nose cavity were not connected. That explains it, thanks for taking the time.

 

[dmaziuk]

I am curious then with this feature "No air from your mouth or nose enters the face cavity" How does one equalize pressure in the face cavity? So the mask is exclusively designed for surface use only?

I believe The Fine Manual says so.

Not that you'd want to equalize an FFM with what you can pack into your lungs...