Gone for diving
Contributor
This is normally what I do when working on customers equipment,I would disconnect the batteries for sure. And pull the small wire on the starter.
Be a good idea to disable the injection pump wire or lock the lever in the shutoff.
To many random people
A boat is harder... you aren't even visible...
Hide the battery is probably the safest for peventing engine starting...
I don't care how many locks and lockout cables you use, you are assuming the person you are preventing from operating doesn't pull out a cordless grinder and cut the locks off.