2005 Supra will not start after running fine

I started the boat, ran for 2 hours and when I got back to dock it would not start. This has happened twice now. It will not start now either at the house. After a while, maybe when I get home it will start. I can start it 5 times. But, when I go to the river and run for awhile it will happen again. The battery shows 12 volts, it read 13 volts while it was running. Please help.

Start a troubleshooting algorithm on the ignition. Confirm voltage to coil and spark at plugs. Do some research.

Consider searching vapor lock as well. Good luck

Fuel injection can't vapor lock. Well it can but it is overcome with the hp fuel pump cycle and return.

Can you share some more details. Does the starter turn?