thruster prop disappeared in 48 hours

[Halifax Sailor]

Have a pwr boater in my marina that lost a thruster prop to degradation early this spring. he replaced with new shaft and prop, launched and the second one disappeared in 48 hours. Lower end on power unit was coated with "salt stains"? I think there is a bad electrical leak either in his boat, marina or very close, electrolysis?? Any ideas as i am a bit concerned. I am close to his boat but not that close. I don't need to replace mine or find out there is an issue. Have multiple anodes on shaft and in motor on my sailboat.

[fstbttms]

Almost certainly this is an issue originating aboard the boat in question. If the powerboat owner hadn't had a marine electrician go through his systems, you might suggest it to him.