CONTINUOUSWAVE

I plan to replace the navigation lamp wiring on our 1989 Montauk [17] as part of a rub rail replacement.

The terminal block that the [concealed wiring under the rub rail] connects to at the stern also needs to be replaced.

Recommend a terminal block that would be well suited.

The existing [terminal block in the stern to which the concealed wiring connects] has a metal cover over the junction.

Should the terminal block should have some extra covering and protection?

Thank you for the assistance and guidance.

The OEM terminal block was probably a classic electronics terminal block. You can find these at many electronic parts vendors. For example, see

https://www.mouser.com/datasheet/2/87/Bus_Ele_TB100_Double_Row_Terminal_Blocks-336804.pdf

Or you can use a newer style, often called a Euro block, similar to what is shown at

https://www.asi-ez.com/member/~ASIMY16HW-1.2-14.6-2P.asp?

The cover protecting the terminal block from the weather was often just a light-gauge molded plastic cover. I don't know of a source for these today. You can use a small molded plastic box instead. HAMMOND makes many suitable plastic boxes. You can also find these from Asia sold on-line. Search on the search terms "plastic small electronics box gasket".

Thank you for the information and references. Really appreciate the assistance.

Hammond electrical boxes can be purchased through authorized online sellers.

Here is a list of the watertite boxes available.
https://www.hammfg.com/electronics/small-case/plastic/1554

On the smaller open skiff boats from Boston Whaler, the circuit for the combined sidelight lamp and the circuit for the aft pole lamp usually met under the cover of the junction box. If you want to be able to independently control illumination of the sidelight lamp and the aft pole lamp, you will need a three-terminal terminal block.