Dan,About five years ago I took part in a UK sailing magazine's test of all available self inflating PFDs in the European market. We had loads of them and six of us spent a whole day either jumping in or falling into a pool. There were two guys from the trade re-arming them as fast as they could. It was just at the time that the British specification was being adopted by the European Common Market ie. a couple of years before the USCG even agreed to allow such things. I had some early ones over 25 years ago but have now replaced them. The CO2 cylinders never loose their gas but those secreted away inside PFDs with Hammar firing gear can go rusty or come unscrewed without the owner being aware. Both causes have killed professional fishermen. Also you cannot weigh them annually without breaching the air seal of the PFD' bladder. No I don't like Hammar firing gear!The outcome of our tests were that all the life jackets quickly inflated every time. None could be set off by playing a fire hose onto the wearer. The Hammar ones which need 4" immersion were slower to inflate, but all functioned within about ten seconds. If you fell into the water face down but with outstretched arms, no jacket was capable of turning you right-side up. However if you went in as if knocked out they all turned the wearer, albeit slowly because of air trapped in clothing. We didn't drown a single volunteer. There are three standards of PFD, namely 100 Newton (25 lb), 150 Newton (33 Lb) and 275 Newton (60 lb). All buoyancy figures.We found the 275 N models too bulky for normal wear as they are intended for men with full working clothes on such as on oil rigs. The 150 N was the yachtsman's size and suitable for open water. The 100 N ones are not proper lifejackets but are classed as buoyancy aids more suitable for rivers and inland water.I would strongly recommend buying ones with a built in harness. This means no additional changes of gear when things get rough. All the harnesses and tethers have to withstand a 100 KG man (220 lb or 17 US Stone) falling 2 metres (6') without the harness breaking. Don't put this to the test as you will break several ribs. Olympic Medallist Glyn Charles lost his life in the Sydney Hobart race because of tether failure.Get ones with a 'lifting becket'. This is an additional concealed loop inside the outer casing which the rescue services will use. It has been found that by lifting from the "D" ring the body is vertical and, in cases of Hypothermia the survivor can die of heart failure whilst being lifted by helicopter due to the blood draining to his boots and starving the heart. The lifting becket causes the body to hang more horizontal than vertical so overcomes the heart failure problem. We all found that 'crutch straps', aka suspenders, were good for stopping the PFDs from riding up over one's face. They gave much more 'freeboard' and were a great boost to confidence. However I saw a gibbet over the dive training pool we were using and asked to be hoisted up out of the water. The trade guys went bananas because the plastic buckles on the straps had not been designed to take the weight of a man. Crazy I know but it seems the spec is only to keep the PFD in place for someone jumping 30' off a ship. I designed stainless steel buckles and gave them to the UK's leading PFD maker. They did nothing with them as they meet the (inadequate) EU spec anyway.Buy a spray hood. The Royal Navy have done trials and analysed many deaths and conclude that survivors drown because they drift head first down wind. This results in a constant buffeting from the waves breaking into the survivor's face so he drowns before hypothermia kills him. I used a spray hood on my PFD and they turned the fire hose on my face. The water pressure drove me very rapidly backwards across the pool but I was able to breath normally.The downside was that it was only 15°F outside and that fire hose was darned cold.Having bought them you and your crew should blow them up, remove the CO2 capsule and TRY THEM IN THE WATER. Apologies for being long winded but others might find this useful also.