RC Submarine Charging Port
There's no telling the polarity of things from the connector itself, so you'll have to figure this out by e.g. measuring whatever comes out of the charger and following the lines/traces inside the submarine to the internal electrical storage.

The "black framed part" really is just a jumper: it shorts toghether the two pins it connects. My bold guess is that it's only the submarine's way of knowing you've closed the lid. (especially since the charging cable is only two wires, these two pins will probably simply be unconnected in the charging connector, but will mechanically make sure you don't connect the charging cable the wrong way around)