If you were to move away or fall from the PWC it will detach from the PWC stopping the engine in the process.
Two handheld orange smoke + 2 x handheld red pinpoint flares OR 2 x day/night flares. If you are in grave and imminent danger do not hesitate to use flares to get help - delay could be fatal in deteriorating weather conditions, when night is falling or after an injury.
To keep your PWC in the same spot after launching and before recovery, when you want to take a break or in an emergency.
For small electrical fires, to assist others.
A mobile phone can be used to raise help close to shore.
VHF: You will be heard by everyone in the vicinity that has a VHF, can be used where there is no mobile phone signal available.
Slipways and seabeds often have sharp nasties lurking.
In order to locate yourself, if fog sets in it will assist you in finding your way. Also useful when looking at a Cardinal Mark Buoy so you know which direction to go.
For the occasion you need to be towed or need to tow someone else. Can also be doubled up as a anchor line or to tie off in a marina.
To cut away weed, fishing line etc from your intake grate
For signalling in an emergency and inspecting the intake / pump housing / engine compartment before launching.
When you arrive at the slipway or between sessions there would be nothing worse than a loose connection or similar stopping play
Put all your items into a dry bag to stop them getting wet and rattling around under the hood of your PWC.