Ever since a treasure syndicate wasted £4,000 worth of explosives on the search for a tin wreck 200 feet down in the Irish Sea, because the divers, using advanced rebreathers, had to surface after 5 minutes due to the cold, I have believed there was a crying need for a relatively cheap hot water system for divers working outside the North Sea. Having tested the one developed by Marine Surplus Supplies I believe one is now available and should begin to be widely used in civil diving.
Michael Cocks tests out the
MSS Hot Water System in the
purpose built tankAs I have mentioned before, the more strictly civil diving is patrolled, the harder it becomes for me to get a dive, so I jumped at the invitation made in the last issue of Underwater Contractor for a free trial of the new MSS hot water system. Watched by two llamas and four sheep, with a cock crowing in the background, I descended into their new purpose-built tank at their headquarters, a converted farm building, half a mile off the M55.
Marine Surplus Supplies were set up in 1984 by Phil Connolly, who began his diving career in the salubrious waters of the Manchester Ship Canal, before moving onto the North Sea with Oceaneering. Submarine Manufacturing & Products was set up seven years ago with Brian Fear, and wandering over their extensive site was like visiting an Aladdin’s Cave of diving equipment.
I decided to use a Superlite helmet, as I was also to try out their new Prothermic cutting rods, which also passed the Cocks test. As it turned out I would probably have been warmer and more comfortable in a band-mask as one of the water tubes could have been passed under the hood. The water temperature was about five degrees centigrade and I stayed in for over an hour and a half. I felt very comfortable and would have been happy to remain for much longer. One added benefit of a hot water suit is that you do not have to come out to answer a ‘call of nature’, which can be a problem for a heavy drinker. When I dived a year or two ago in a similar tank, that time indoors, in a dry suit, I found the cold made it hard to concentrate after about an hour. This system will support two divers down to 50 metres and is easily transported.
The most impressive part of the exercise was the speed at which the temperature changed as the controls, which are set at 2 degrees centigrade intervals, were altered. Using the dump valve I began to feel cold after 30 seconds but noticed a change upwards in temperature after about a minute. Obviously the deeper one goes the greater the heat loss down the hot water tube - in fact in this case, at a depth of 4 metres the loss was 10 degrees. The system has been used recently in Spain in a dam, with a booster pump, down to 100 metres.
The vital determining factor for an onshore diving contractor is the cost. The SMP mini portable hot water system and a hot water suit etc will cost under £5000 (inc vat) and running costs on diesel are about £2.50 per hour. An added advantage for the diver is all he would have to provide is his own undersuit and the hot water suit is more durable than a dry suit - a tear does not mean he will spend an uncomfortable dive. Of course the system is not suitable for use in heavily polluted water but, despite a warning that fresh water would cause my extremities to shrivel (and wrinkle more than usual), I emerged unscathed.
It is good to see a new piece of equipment, sold by a British company, which is shortly to open a branch in New Orleans, and even now gets almost two thirds of it’s business overseas. Phil Connolly was disappointed that the weather was relatively mild but I have offered to try the system out for a prolonged working dive under ice and Phil is so confident in the product that he is prepared to make the following offer to any contractor reader of Underwater Contractor: to provide the use of the system, with an attendant, on a trial basis.
Michael Cocks.
