I'm truly fascinated by this thread . I've taken a dip at almost every marina around here .every one of them has been ,at one point heavily damaged by storms lightning strikes so forth , and there is some major electrical power running through these ,huge distribution boxes feeding all those boat lifts shore powers slip fridges 60" flatscreens ,and I have seen corrosion that didn't make sense on a fresh water app .now I have to build something to detect these currents and start snooping

not only stray electric current(s) but the marina areas hold more toxic water than any other area of the waterway. leaking oil, gas, battery acid from what ever source, also engine emissions - engine warm ups & long periods of idle of the engine makes it even worse. marina area water tends to be more stagnant,

Also people's litter for everything, plus crap & pee. then you can factor in the boat traffic and how many boaters coming back in to dock were drinking heavy. What was that - I think you just chopped up a very small child swimming with your props. Really swimming in the marina who would ever thought that could happen ?

Man the toxic water just finished me off ! I have a few slips I sub out at a few marinas ,sometimes I just slip in thewater and get er done ,Volvo 280 t&t latch gunked cav plate adjustments ect .usually on a weekday though ,the pee has a chance to dissipate but yea I see people swimming there all time .except sneaky Pete's .they have 2 pools lakeside .

A related stray electricity matter of note. If there is a fault in wiring and you are using a pig tail to power up shore power while on the hard. Watch out for hot shafts and rudders due to bonding wires. A buddies cruiser was on the hard and he had some rudder work done. It had been raining lightly all day. I bent down to check the work and ran my hand over the repair. Yeahhhh! I got twisted up something fierce! It's okay to laugh guys lol. I'm laughing as I remember it. Joking aside stray current is a serious issue. Play safe out there.