Alternatively, there’s “keelhauling”...the guy this way at least has a chance ( assuming that the ship’s engines are stopped)
Interestingly, there’s no reliable evidence of keelhauling ever being used in the Royal Navy, or the services that descended from it. It was used in the Koninklijke Marine (Royal Netherlands Navy) and by pirates and similar groups, but it never official status in any Navy of Britain or its Empire, and while there are plenty of claims it was used, nobody can actually seem to cite a case.
Plenty of other brutal punishments were permitted.
So what intel of value did he give them?
Give me thirty minutes with him in his cell with a blow torch and pliers and I guarantee he would be sorry.