120V-15a (household) plug behind plastic cap in transom

[Esmi2]

On my new-to-me 2006 Cape Cruiser 23, I have a plastic cap in the transom just below the engine. Under the plastic cap is a 120V-15amp plug.

When I put power to the plug, nothing happens. When I put power to the plug AND turn on the inverter switch at the helm, I get power to a 120V outlet on the starboard side of the cockpit (and nowhere else that I have been able to determine).

Can anyone help me determine what the nature of, and benefit of, this circuit is? What purpose does it serve that would make my boating experience better?

It seems completely separate from the 120V-30a twist-lock circuit that powers the rest of the boat.

Thank you.

[thataway]

This would have been installed by a previous owner--not factory. My best guess is that this is an inlet for a battery charger. I have had several small boats which had this setup.

[Robert H. Wilkinson]

https://inverterservicecenter.com/products-by-brand/marinco/battery-charger-inlets

If its a plug like this its usually something found on bass boats for their onboard charger. It is hard wired directly to the charger only and must never be wired to any other live source. A live male end is very dangerous and illegal.

I requested one installed when I ordered my new boat. The marina refused to install it as they did see it meeting code and didn't want to be liable.

Rob

[Esmi2]

Thank you, gents.

I will need to go research it a little more closely. It makes perfect sense that it would power the battery charger (which resides in the transom locker nearby). But it doesn't. It runs past the charger and into can't-see-ville. By observation and process of elimination, I thought I had discovered what it did (without discovering WHY it did it). But now I am thinking I missed something. Stay tuned...

[ssobol]

Are you sure is it not an outlet from the inverter to get 120ac into the cockpit?