I had a Merc that feed the water heater from the block drain port going in and the water pump housing on return. I don't have a VP 5.7 cooling system manual so I would guess which ever ports where used for open can also be used for closed unless the outlet went to the exhaust elbows
Which 5.7...
Many are installed this way because the Red wire terminal is not large enough to connect direct to starter post. In Merc documentation it list Red as Bat power unfused and Red/Purple Bat power fused
Check the voltage on the other side of the 50 amp breaker
If it deals with the motor running it stays on the start Bat, as in key switch, gauges, starter, alternator, power trim, etc
If it's for any other stuff, this can go on the house Bat
For the most part no adhesive is needed for any of the O-rings to create a good seal. The adhesive is only used to help keep the ring in place during install. If the ring moved it could pinch it and cause a leak
Your ALT will rarely output full amps, and you said it's 6 feet (double 12ft). So using double that and it's non-critical 6 awg will be plenty and 4 awg is even more
ok I get it, where your life jacket
Reminds me several years ago running the Ohio river and noticed a guy flagging me down. Older gent was taking on water in a jon. Towed him to shore and went on my way. About an hour later I'm headed back the other way and same guy is back out there fishing
Welcome
I would remove and sell it to get your $300 back and most likely make enough to pay to have the boat hauled off to the dump. The boat is not worth fixing
Don't use bed liner coating on the hull, it will not last and will create more drag