I bought a couple of second hand life jackets from a seemingly honest friend of a friend. The jackets looked immaculate and the story was they had been bought 4 years ago but then the boat was sold and they had never been used.
Because of their age I decided to service them anyway and was horrified that both cylinders had been punctured and both water sensors had their green caps off as they had fired at some point.
https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1 added £18.45 per jacket to the seemingly bargain price I had paid, but important lesson learnt.
For info, servicing yourself is dead easy and you know for sure its been done. instructions are on a big label inside the jacket, or more detailed instructions in the booklet that came with it, or download from manufacturer web site if lost.
Not only Crewsaver but many other brands of jacket use the United Moulders mechanism and the united moulders service kit linked above is cheaper than the Crewsaver/Yak or whatever branded spares.
A manual jacket is cheaper to run than an auto inflating one as the cylinder is the only consumable and they last years if not used. Just weigh them annually to check they are still full. Water sensors are check annually and replace at the expiry date 3 or 4 years hence.
Safe boating!
Pete