Does this mean that the liferaft is a use-once-only item and that once inflated using the gas cylender must be thrown away?
It probably means the liferaft should be overhauled by somebody competent, after it has been used for real.
Though hopefully that is not WHY you are floating around in the sea!
Usually that is precisely why one is
I think most ditchings are caused by running out of fuel. Especially on the Jersey runs which people tend to do with nearly empty tanks so they get the biggest benefit of the cheaper fuel
They just neglect the fact that if they left the UK with full tanks and claimed the duty drawback, they would make a similar saving and have a much safer trip and would in most cases avoid a pointless stop in Jersey which is just unnecessary hassle.