Appeared in DIVER March 2007

ITS OFTEN BEEN OPINED, on the great Misinformation Superhighway that is the Internet forum, that diving manufacturers rip us off. For example, why does an electrically heated vest for diving cost so much more than one for use by motorcyclists
I answered that question when I tried the Typhoon Icebreaker in Stoney Cove one winters day, and the drysuit that had come with it completely filled with water.
I still managed a 45-minute dive in what became a heated-water suit - until, that is, inevitable chafing caused me to call it a day. I was neither cold nor fried, nor was my hair standing on end.
The Thermo heated waistbelt uses similar technology to that of the Icebreaker, in that clever flexible polymer panels containing thousands of conductive particle chains are connected to electrodes which, in their turn, are evenly spaced along internal panels in the neoprene waistbelt.
You wrap it round your waist and it is fastened by Velcro tabs.
A flow of low-voltage electricity energises the particles, which become agitated, increasing the electrical resistance and producing heat. As the resistance increases, so does the heat, until a maximum temperature of 42C is achieved.

UNLIKE THE ICEBREAKER, THERE IS NO THROUGH-DRYSUIT connection to an external battery. The whole thing runs from a small 12V battery that is switched on before you zip up your drysuit. It has a duration of around two hours.
Also unlike the Icebreaker, the lithium-ion battery is inside your suit with you, so severe flooding could cause problems.
Lithium-ion has a habit of getting very hot when it gets wet.
I still have the burn mark on my desk from the last lithium-ion battery I flooded. It would certainly warm more than your kidneys, so you want to avoid a total flood at all costs.
Of course, most of us merely suffer a wet chest area or soggy wrists. For the water to get down to your waist, you would need to pull open the neck seal, which is likely only if you found yourself doing an uncontrolled ascent.
That aside, I found the Thermo agreeable to use. It didnt appear to get hot, yet it left me with a warm feeling about my middle.
Not only that, but I found that I was just as inclined to use it while riding my bicycle to the office in the January chill, as I was to strap it around me before donning my drysuit undersuit and going diving.
If you punish yourself by diving at freshwater inland sites during the winter, it could prove to be a better investment than a hastily scoffed bacon sandwich and a woolly hat worn after diving.
The Typhoon Thermo costs 129.
  • Typhoon,

  • Divernet Divernet
    + An economical alternative to the more expensive Icebreaker

    - Flood your suit with this inside at your peril!