Vest, Typhoon Icebreaker heated vest

Battery, or just pleased to see me
It was not the coldest of February days, in fact it was quite balmy. The water at Stoney Cove was as clear as I have ever seen it and as warm as a bath - a bath drawn by an Eskimo and left outside all night to chill. I was wearing a drysuit borrowed from Typhoons bull-necked export manager. It fitted me perfectly - apart from the neck seal.
     People argue about the merits of auto-dumps versus cuff-dumps. I had a neck-dump. As long as I stayed with my head at the lowest point of my body I stayed dry, but that was impractical. So whenever I looked up to see where I was going, the air from my suit gushed out and water gushed in.
     I swam over to the wreck of the Stanegarth and some distance beyond before boredom overtook me. We were about 20 minutes into the dive. I signalled to my buddies that I was going back and they followed. I never had to worry about dumping air. My gradual ascent seemed to be accompanied by as many bubbles from my neck as from my regulators exhaust valve. After 40 minutes I was so wet that my underwear was chafing and finning was uncomfortable. It was time to get out.
     Was I cold Well, no. I was wearing Typhoons new IceBreaker electrically heated vest beneath my undersuit, and my test revealed that it will probably work as well with a wetsuit!
     In fact I was so warm that I wished Id had the foresight to put some PG Tips inside my suit. They would have brewed nicely by the time I got out and, instead of tipping half the Cove onto its carpark, we could have all had a nice hot cuppa!
     Ive tried electrically heated undersuits before. They have proved comfortable and effective but as they needed the intelligence of a micro-processor always proved beyond the financial reach of the leisure diver.
     Hi-tech meant high retail price but the IceBreaker is hi-tech in design but low-tech in operation. It uses a flexible intelligent polymer containing thousands of conductive carbon particle chains in panels within a neoprene vest which, with the aid of Velcro-covered sections, can be adjusted to fit almost anyone.
     You wear the Icebreaker under your drysuit undersuit and over a cotton T-shirt.
     Power is supplied as a rapid pulse. The designer promised that it could be completely soaked and, as it contained no electrical components, would still work safely. Well, I proved that correct!
     The current flows and it gets warm. Its that simple. It uses so little power to heat up that a relatively small 4A/h lithium-iron battery is used. That holds enough charge for around 70 minutes and more.
     Ah, I hear you tek divers say, I dive for much longer than that. Well you dont switch it on until the last part of your dive, or you carry more battery power.
     Well, what if I leave it on and it burns me Thats where the rocket-science comes in. Loading the polymer at the heart of the heating component with conductive particles enhances its conductive properties and results in the element exhibiting a positive temperature coefficient when heated. A characteristic of the material is that its resistance varies according to its temperature in a non-linear way.
     Once the material reaches a certain temperature, it self-regulates. The conductive particle chains in the suit vibrate when the current flows. They get warm but the hi-tech material that forms the heating element will not exceed 42ÂC. Thats warm, but not warm enough to cause discomfort. So my tea would have been tepid!
     With no thermostat, how do you turn it on and off You must adapt your drysuit by punching a 13mm hole through its outer fabric to fit the electrical connection. On the inside of this waterproof bulkhead connector is a lead and plug that connects to the heated vests lead. On the outer side is a two-pin (plus guide-pin) waterproof connector. Mount the battery-pack where you wish and feed its lead to this. Connect when you get cold. Disconnect if you feel too warm.
     The wet-connector comes with a blanking plug-end to the battery lead to stop unwanted discharge through the water over the longer periods when it may not be connected. The battery-pack is small enough to fit a BC pocket. The best place to fit the bulkhead connector is on a thigh, as you can see it and get to it easily. My borrowed test drysuit had it mounted on the chest, which meant stripping away the cummerbund of my BC to find it. Not so convenient, but in the circumstances I preferred to leave the heating on.
     So 10 out of 10 to Typhoon for the IceBreaker heated vest but 0 out of 10 for not supplying a suitable drysuit with which to try it. I cant wait to try it again but with a suit that will keep me dry as well as warm.
     There will be many applications for this product outside diving. People may soon get in the habit of saying to those who work outside in winter, Are you pleased to see me, or is that just a battery-pack in your pocket
The Icebreaker retails for around £499, including battery-pack, connection kit and charger.

  • Typhoon International 01642 486104

  • Divernet
    + An affordable heating system
    + Proved to be safe when wet

    - You need to turn it on and off manually to suit