Coldish water snorkeling/diving

[orangetallguy]

I work for a consulting firm and at some point in the next few weeks my team and I am going to have to do some extended in-river work (likely only 4-5 feet deep at most) in 50-55 degree water. The work consists of mostly sitting on the bottom of a river and characterizing the streambed and animals that inhabit it. There isn't a lot of moving around and you can get chilled pretty quickly. We did it for a few days last October when the water was around 48 and it was miserable. Based on last year's experience, I have been against the project from the start due to exposure concerns, but I have been over-ruled by the higherups.

Most people on my team will be in 7mm wetsuits with lavacore underneath and 5mm hoods (drysuits aren't an option). In these suits, my crew was making it about 30 min before having to get out and warm up for an hour or so.

My question is... How long can I realistically expect my field team to work in the water each day? I am basically trying to find a balance where I am not putting my crew in a bad spot and keeping them in the water too long, but at the same time, working long enough days that the project doesn't drag into November when it would be brutal. I know its never good to put people into cold water when they don't really want to be in it and I'm just trying to make the best out of a bad situation.

 

[spectrum]

Investigate sodium acetate heat packs or those newfangled battery powered vests, a buddy test drove his and has thumbs up.

 

[Akimbo]

I can stay comfortable 5-6 hours in that temperature water wearing a 2-piece 7mm freediving suit, especially in such shallow water. The right suit can make all the difference as long as you are not in and out of the water. Getting out even waist high lets the water warmed by your body leak out and you have to heat another batch. Good luck.

 

[Dive Right In Scuba 2]

The bottom line is that cold is a factor of time and no matter what exposure protection is used, immersion times can quickly become a safety concern. While I cannot speak for the cold tolerance of your team a few years back I was involved in a research assignment off the coast of NC in similar water temps. Wearing a 7mm farmer john we would average about 3 hours of tolerable BT daily. Mind you we were working and moving while under water, so you may be looking at a max of 90 minutes to 2 hours daily while sedentary. While warm drinks like coffee etc.. may make you seem warmer they actually dehydrate you obviously, robbing your body of peak performance. I would opt for hydration with good old fashioned water along with healthy snacks. In addition, be sure to have people on your team well trained in recognizing symptoms of cold distress and treatment. Good luck to you, it doesn't sound like a fun assignment.

 

[lamarpaulski]

Warm water pumped/poured into wetsuits can be a solution or at least a big help. Just make sure its never scalding hot. Even some kind of large "cooler" (which can act like a thermos) could be floated nearby and accessed to warm up the inside of your wetsuits. Your imagination can take it from there with pumps or tubing or a simple big gulp to put warm water in. A propane camping stove can easily keep the 'thermos' supplied with the warm water in remote locations...just use river water....again you must be sure its not scalding hot.

You might dedicate a person as the warm water supplier/ keeper of the flame. They will be popular.

No doubt you can buy commercial warm water pumping equipment but yours seems like a shoestring operation.

Its a nice remedy to putting on a cold clammy wetsuit in the morning too. I used something similar to extend my cold water wetsuit diving years ago. Its also quite cheap.

 

[Akimbo]

The strategy can be in two parts. Preserving body heat and restoring it.

Cousteau’s book, the Silent World, describes one of the most effective methods to restore body head, and is not unlike what hospitals do treating hypothermia. They found the best is the modern-day equivalent of a hot tub and drink hot non-alcoholic fluids. The second was to sit between two camp fires with hot drinks. This allowed them to make repeated freedives throughout the day before wetsuits.

 

[Steve_C]

Stay covered up when out of the water. A wet suit turns into a refrigerator when out of the water due to evaporation. Wear something waterproof over the wetsuit if you have to leave it on.

Put neoprene socks inside the boots. Cuts down another source of loss

Get heavier wet suits. I did some shore dives north of Vancouver in 49 degree water. Wore a 10/14 wet suit and was comfy for two 45 minutes dives.

I find that keeping my arms in next to my body, if possible, cuts on heat loss somewhat at any termperature. May not be possible with your work.

Wear warmer gloves if you can.

 

[MAKO Spearguns]

I work for a consulting firm and at some point in the next few weeks my team and I am going to have to do some extended in-river work (likely only 4-5 feet deep at most) in 50-55 degree water. The work consists of mostly sitting on the bottom of a river and characterizing the streambed and animals that inhabit it. There isn't a lot of moving around and you can get chilled pretty quickly. We did it for a few days last October when the water was around 48 and it was miserable. Based on last year's experience, I have been against the project from the start due to exposure concerns, but I have been over-ruled by the higherups.

Most people on my team will be in 7mm wetsuits with lavacore underneath and 5mm hoods (drysuits aren't an option). In these suits, my crew was making it about 30 min before having to get out and warm up for an hour or so.

My question is... How long can I realistically expect my field team to work in the water each day? I am basically trying to find a balance where I am not putting my crew in a bad spot and keeping them in the water too long, but at the same time, working long enough days that the project doesn't drag into November when it would be brutal. I know its never good to put people into cold water when they don't really want to be in it and I'm just trying to make the best out of a bad situation.

Please consider our freedive suits. Our two piece freedive suits are made of the best quality neoprene: Yamamoto.. stong and flexible... A freedive suit is very warm because we have no zippers, an attached hood and a smooth rubber interior that reduces seepage of water into the suit.

We offer 3, 5, and 7 mm suits.. To be honest, a 7 mm is probably over kill, but if your divers are going to be stationary and generating very little heat, then the 5 mm suits might be a little chilly after an hour or so.

The 7mm (with appropriate warm gloves and boots/socks) they should be good for 2 hours or possibly more. Having hot water available after a dive will also help in comfort.

Yamamoto Reef Camo 2-Piece Open Cell Wetsuit | MAKO Spearguns

check out this crazy river diver using our MAKO 7 mm suit:

[video=youtube_share;4d9eW0tRIho]http://youtu.be/4d9eW0tRIho[/video]

 

[Akimbo]

Water circulation is a bigger problem in most wetsuits than the insulation value of the material. One of the big reasons that freediving suits are so much more effective is they use a split-cell interior (often incorrectly called open cell, which is a sponge) material. All those little split cells act like suction cups inhibiting circulation. You MUST use a suit lubricant to get in them. They don’t have zippers to leak and the hood is attached to hinder water circulation.

A non-perfect wetsuit, like an off-the-rack rental, will usually pump water in and out of the suit when you move limbs. The problem with freediving suits is very few places rent them and they are not great for Scuba because they don’t handle prolonged compression very well.

 

[TMHeimer]

I'm no expert, but if possible use 3 fingered mitts if they are good enough for the dexterity you need. All the advice above makes sense, especially that on warming up during surface intervals. Air temp. obviously has a lot to do with it. Generally, the 90 total minute idea seems pretty good. The main problem may be that crew members may vary greatly in cold tolerance.