Dry Suits vs. "Dry Suits"

Hey guys --

Being new to diving but from a fire/rescue background, I was shopping today on a FF supply website and saw something that caught my eye.

Stearns markets a drysuit (Rapid Rescue Extreme) to emergency service personnel.
Stearns Drysuit from TheFireStore.com
Manufacturer Link

I see no mention of an air inlet, however their is an air purge valve. I assume this is to vent air encountered upon donning the suit as the suit is compressed. What other differences exist between a product like this and a dive shop offering -- other than price. Is there a reason that this suit could not be interchanged garment for garment with a wetsuit? (accounting for added buoyancy)? If so why?

Thanks for the help in figuring this out!

G.S.Miller

I'm not an expert (swam in a dry suit for the first time last night, in fact) but since nobody else has chimed in so:

My guess is that this suit is designed for surface activities, not diving. I was given a similar one to wear while white-water rafting earlier this year.

Without an air inlet valve, the suit will pinch against the body under pressure. This uncomfortable even at swimming pool depths (as I learned first-hand). In addition, the *volume* of air among the fibres of your undersuit provides insulation. You need a way to compensate for the decrease in that volume under pressure.

Venting excess air after donning the suit can be done by putting a finger under the neck seal, and crouching. I guess there must be surface situations where you find yourself carrying excess gas (beans for dinner? ) and need to vent.

The term "waterproof yet breatheable fabric" is interesting.

One thing I have noted on other boating/survial suits in the past, including those made by sterns is that the fabric is often a bilaminate (worst case a urethane coated packcloth) that is far less heavy and durable than the trilaminate fabric used on a dry suit intended for diving. Some of the suits are intended more for spray protection than immersion under water and the fabric used would be critical.

At the other extreme some survival suits use heavy neoprene fabric and offer warmth but not mobility. That however is not the case here.

Beyond that, you add an inflator valve and you'd probably be in business.

gsmiller:

Hey guys --

Being new to diving but from a fire/rescue background, I was shopping today on a FF supply website and saw something that caught my eye.

Stearns markets a drysuit (Rapid Rescue Extreme) to emergency service personnel.
Stearns Drysuit from TheFireStore.com
Manufacturer Link

I see no mention of an air inlet, however their is an air purge valve. I assume this is to vent air encountered upon donning the suit as the suit is compressed. What other differences exist between a product like this and a dive shop offering -- other than price. Is there a reason that this suit could not be interchanged garment for garment with a wetsuit? (accounting for added buoyancy)? If so why?

Thanks for the help in figuring this out!

G.S.Miller

Click to expand...

It's hard to say exactly what it's rated for since there are so few details (I checked out the ad). For sure you would need to add an inflator valve/hose and the air purge valve looks to be an old style manual exhaust valve at best. Who knows if the zipper is rated for diving depths and just from the pictures the neck looks a little weird. Supposedly it has a latex neck seal but from the pictures it doesn't look right to me anyway. It's probably a bilaminate rather than trilam.

The bottom line is that there are bottom end (cheaper) drysuits out there made for diving in the <$800 range. I believe OS Systems has a cheaper suit.