Stuart Andrew offers a few tips on what to do when your outboard is submerged.
When your motor is submerged you can leave it under water but once it comes out, you have about 3 to 4 hours to get it going. Once out of the water damage sets in from the air on the inside parts.
Even if you are not mechanically minded you can still save your motor, especially if it is small and easily handled. All you need to do is drain all the fuel and oil, remove the spark plugs and submerge in fresh water. Keep turning the engine around until there are no bubbles coming out. It can stay under till you can get it to a dealer.
If you are mechanically minded, you can do the same as above, but you can drain or clean out the carbs, fuel system and clean all wiring plugs. Put in new fuel and oil if a four stroke. Put in small amount of oil in the fuel if it’s a 4 stroke and double mix if a 2 stroke. Pull over the motor with the spark plug out till the water stops coming out. Replace the plug and start the motor in a tub of water or on the boat. Run the motor for about an hour to remove excess water inside of the motor.
With larger engines, do the same as above, but you must replace any damaged leads or looms and clean out starter motor. With the fuel injected motors, the fuel system is sealed, but you still will need to clean it out. With the larger injected motors, do not put any oil in the fuel. With all motors you should always get the motor checked with a dealer, to see if there is anything you did not see.