After traveling in deep water it ran and restarted. Next day battery was dead, jumped off and started up, charged the battery and battery tested good. The next morning it started and ran fine and that evening the battery was down again.
The alternator is mounted low on the right side of the engine, sounds like it didn’t survive the bath.
the alternator putts out 14.7 volts.
Then something else has shorted out. You need to run a parasitic draw test.
Check for a popped fusible link between the alternator and battery.