First Dry Suit Dive.. anything I really need to know?

[ajames54]

My wife and I will be diving in the St. Lawrence next week (Les Escoumens (sp?)) and we have been told by the dive guide that we will need to dive Dry Suit because the water is THAT cold.. 1 to 4 degrees Celsius.
They say that some people choose to dive in 10 mil Farmer Johns but those people are few and far between.

Neither of us has ever dived Dry suit before .. I know there are buoyancy issues but are there any other things that I might need to be concerned about? (These will be fully guided dives and both my wife and I are familiar with Cold water (using the above mentioned Farmer Johns).

Or should we ask the charter if they can make the diving part of the Dry Suit specialty..(it would be the NAUI course).

 

[teknitroxdiver]

Not really any need for the course, IMO.

Do a weighting check beforehand if at all possible. Most likely you will need a significantly greater amount of weight. Courses like PADI and NAUI's course teach you to use the drysuit for buoyancy control...this sets you up for problems right away. You now have a huge air bubble that is chomping at the bit to race down to your feet and cause major problems. The ideal useage is to add just enough air to reduce the squeeze. When you exit the water it should look like the suit is vacuum packed on. (Keep comfortable of course, no need for blood blisters from having excessive squeeze) Keep the automatic dump valve all the way open and it'll take care of itself pretty much.

Likely you will be more comfortable in the drysuit than in your thick wetsuits....as such I would advise NOT to use the 10mm farmers...that's 20mm of neoprene...think michelan man in a straightjacket.

 

[Tom Winters]

There are some tough Canadians up there. Down here in southern Florida, there are more and more drysuit divers in the winter months, and we're talking maybe 50° on the absolute worst and coldest of waters.
But wow, you would be soooooooooooo much more comfortable in a drysuit up there. Yes there is some expense, although last time I checked, those superthick wetsuits aren't given away at gas stations.
There are some great drysuits manufactured up there - Abyss for one where you don't get slaughtered by the exchange rate. Take the ...er, plunge and spring for the drysuits - think of all the money that you'll save from repairing all those chattered teeth.
http://www.abyssdivingsuits.com/

 

[markfm]

What part of the St. Lawrence? There's good mixing, and the water is quite warm, at least near the mouth (1000 Islands).

Alexandria Bay NY, where I81 crosses to Canada, is 76F (> 24C). It hasn't been 4C in that area since mid April.
http://www.ndbc.noaa.gov/station_page.php?station=ABAN6

As a river, there's good mixing -- no thermocline issues, so the WTemp stays pretty consistent.

I'm diving a 5mm core warmer there (nothing else), others seem quite fine in a normal 5 mm wetsuit.

(Maybe it's different if you're going to the Atlantic outlet of the river, I just know 1000 Islands, though temps out to Cardinal in Canada are reported about the same)

Have fun!

 

[CUunderH2O]

I was at Les Escoumins on the August long weekend, and the water was very cold, between 37 and 39F all weekend. I was wearing a drysuit & still was cold.

ajames54: If you and your wife can try out drysuits in a pool back home before you leave, please do so. By your post I'm assuming you're renting them when you get to your destination. Your LDS should have some suits available to try out, if not, find another LDS that does. Trying out a drysuit for the first time in very cold water is not something you want to attempt, especially if you're doing deeper dives. There are some things you need to know, like the fact that venting air from your suit is a slower process than venting air from your BC. You also have to coordinate managing the squeeze in your suit while still managaing your buoyancy using your BC. If you add a camera to that mix - will you be taking photos? - that again adds to the task handling. An actual drysuit course is not really necessary; a drysuit 'orientation dive' is really all that's needed. Get someone who dives dry to help you in the pool.
And have fun on your trip.

 

[Doc Intrepid]

There is one small thing....

Drysuits are not like BCs. If you put too much air into a BC, its relatively easy to dump it all if your ascent gets away from you.

This is not the case in a drysuit. A number of reasons include the fact that it has arms and legs, you may be in a position where the valve is not at the highest point, it tends to hold gas inside it (unlike a BC) in wrinkles and folds, and in general the dump valve may have difficulty trying to dump an OVER-INFLATED amount of gas rapidly should your ascent get away from you. That much gas simply expands as you rise faster than the valve can exhaust it all.

So....

Two things to think of (in addition to ensuring that your automatic valve is turned open all the way):
1. Dive the suit tight. More air in the suit is warmer, but much more unstable - it moves up and down inside the suit as your attitude in the water column changes, it feels like critters running up and down inside your suit, and it makes it more difficult to hold perfect bouyancy and trim.

2. Control your ascent. Ensure your trim is good, your ascent is slow, your valve is high and automatically dumping, and simply don't ascend fast - let that valve dump the gas as you ascend nice and slow.

You'll get a better feel for it after a few dives, but you'll also see a few new drysuit divers doing the inverted polaris launch as they let the suit get away from them. Best to avoid that from the start.

Enjoy your new suits.

Doc

 

[String]

this sets you up for problems right away. You now have a huge air bubble that is chomping at the bit to race down to your feet and cause major problems.

Only if chronically overweighted which shouldnt be the case. If you have a huge bubble, you have too much weight.

 

[trevinkorea]

Drysuits do take a little getting used to but they are very managable provided you've got a good buddy.

If you are using a rear entry, remember that your buddy is going to have to unzip you so stay on good terms. I now dive a self entry for this reason. And, of course take a trip to the rest room right before the dive. Drysuits are unforgiving in this regard.

 

[teknitroxdiver]

Only if chronically overweighted which shouldnt be the case. If you have a huge bubble, you have too much weight.

Okay, maybe HUGE was a little out of place. But, it's a lot bigger than if you were using your DRYsuit to stay DRY and your BC to Compensate for buoyancy changes. Also the air has more room to 'run around' than inside your wing.

 

[Daryl Morse]

Most of what you need to consider has already been said. I particularly concur with Doc Intrepid to dive the suit reasonably tight while you're becoming accustomed to it. By reasonable, I don't mean you should feel constricted in the suit.

Another piece of advice is to practise dumping air from the suit before you decend to your intended bottom depth, just to get a feel for how the dump valve works. Some drysuits are fussy about how you must be positioned in the water for the dump valve to work. I dive with a Whites drysuit with a shoulder dump. Unless the dump valve is oriented almost directly upwards, it will not automatically dump. Your suit may or may not be the same. (If you have a choice, get a drysuit with a cuff dump!)

Enjoy being warm and dry!