He is stupid, yes. But I think he might have been talking about electro magnets that get damaged when not properly protected. It is about the aircraft carrier that used it as a new launch system. Water, saltwater at that and there were some problems reported. I am sure the engineers are smart but a new system always has problems. Orange brain goes "bad tech" orange mouth goes "blaaargh".

Yes of course. That is the reason why you can put magnets under your foreskin under water and have nothing to fear under water, like getting hurt when metal comes nearby /s

Well, electromagnets don’t work when they short-circuit in water…