1988 sea doo

There's relays for the system located in covered fuse/relay box

There might be a batter disconnect switch near the starter wire , follow that wire back to the source.

Perhaps.

I suggest you test the theory by bypassing the relay and/or energising the starter motor manually using a jumper lead, a suitable screwdriver or similar or a remote starter switch.

Could be the starter motor, a bad solenoid or bad battery connections.

If engine cranks but will not start then you have ignition and/or fuel delivery problem. If it does not even crank then you have to include the starter/solenoid, motor into the equation.

And if the ignition was on when the car went under water you may have toasted the computer - definitely not a good thing and very expensive to replace!

Basically, you are in deep doo doo.

Take out of storage and float off trailer into water

Starter clutch

fuel filter,fuel pump.battery connection.

The start circuit from the ignition switch to neutral safety switch to the solenoid on the starter might be bad. Look for power there at solenoid or at neutral safety switch when it doesn't want to crank over.

Check the ignition switch, and the wiring to the starter solenoid. Get someone to turn the key to the crank (start) position and check for voltage at the starter solinoid. Check the starter relay and all fuses.