John, you really asked me a difficult question. I have been in –15 or -16 C but it is more headaches than fun. On the other hand I try not to get discouraged by cold whether, I love diving too much. Last week on one particular windy night we had a whopping –25C. If I can I would avoid the ice, as it is more headaches.
You couldn't put it any better, John -- It's not the water it's the air temperature. The wind is a big player in this. I can give a whole list of things that can go wrong in cold temperatures. John fill in where I miss please.
> Free flow (common)
> Frozen BC inflator or suit inflator
> Broken / ripped dry suit seals
> Don't bend the hoses too much
> Don't spit in the mask - spit in the mask and keep a quantity of water in there until you're ready to dive. Don't leave it there for eternity or you end up with an inch thick lens.
> Don’t pull on the fin or mask straps like you do in Florida.
> Make sure the batteries in the lights and especially computer are GOOD - if they are almost on the way out they WILL CERTAINLY die in the cold.
> Do not touch cold metal equipment with bare hands.
> Don’t put the car keys in your mouth
> Cheap watches will not work usually.
> Cameras will not always wind the film.
> Don't hoist equipment up a quarry face with a wet rope. It wouldn't last.
> Watch the rocks on the shore; there might be a thin (very slippery) sheet of ice. This happens if the water isn’t frozen yet.
> Don’t dig a hole in the ice with your dry suit on.
> Don’t drive on the ice unless it is a good 8 inches thick.
> Have a warm drink (NO ALCOHOL) ready for after the dive.
> Always use a limited length of rope for ice diving.
> Use a Jon line directly to the safety line, if buddy is tied to it.
> Your safety diver should have a good extra length on his line. Safety diver is mandatory for ice diving.
I suggest drive up with your under garments on. Take a spare change just in case. Rig up the regulators and BC at home and throw the whole thing in the back seat of your car. NOT THE NIGHT BEFORE!!! I have an SUV so mine goes in the very back. Keep the vehicle running and slip into the dry suit, hood and gloves and rinse the mask. Don’t inhale the exhaust it is not good before diving LOL. Prepare the fins and the computer then throw on the tank with the instruments on. Put your computer fins and mask on, lock your car and jump in without wasting time. DON'T use the regulator in the surface. Submerge right away and then start breathing. Don't hang out side or exposed for the wind, with your gear. You would regret it.
Once the dive is over just dry the BIG melon so you wouldn't get cold and store your equipment away from the cold air. If you leave the gear in extreme temperatures it would get a good beating. Things that you don’t see – nylon seats inside regs will become like brittle, etc.
___________________Wind factor chart_____________________
Temp>4C2C1C-4-7-9
3to621-4-7-9-12
7to101-7-9-12-15-18
11to15-4-9-12-18-20-23
16to19-7-12-15-18-23-26
20to23-9-12-18-20-26-29
^Wind speed in Knots
eg a -9 deg C temperature can feel like -29C in a wind of 20 to 23 kn.
As far as equipment goes, I use Oceanic DX4’s with Delta sub Zero’s. They still free flow when I abuse them. I also want to stress out the use of a pony bottle. I usually dive with a 16L and a 4L pony in the winter. By the way the 16L is equipped with an H valve so I can shut down the offending side. If that wouldn’t work then I rely on my short friend, 4L. I leave the twin tanks for summer.
Enjoy the winter months and be good for Santa :-)
Lawrence