On deck stepped masts the cables for the masthead instruments, antennae and lighting have to leave the mast at deck level and then travel through the deck to their destination below. This has to be achieved without allowing water below decks along with the cables.
One way to do this is to terminate each cable with a plug and fit mating sockets on the deck. The plugs are, however, notoriously prone to corrosion and to damage from
being stepped on.
A better way is to take the cables through the deck before making any joint, if a joint can’t be avoided altogether.
Deck glands of various types are available – they are designed for individual cables or small groups of cables. The best types allow you to pass a connector, such as a PL259 coaxial cable connector, through the gland without the need to separate it from the cable. These glands are expensive and prone to damage from being stepped on. They are also not entirely reliable over time and you often see them supplemented by globs of silicone sealant in an attempt to restore their integrity.
Another method of getting cables below deck is a swan neck pipe. This is a popular method on bigger boats but it can look a little ridiculous on smaller boats because of its size. The major functional drawback of the swan neck is that it snags lines.
A better option is the Cableport, a Swedish design in use on thousands of boats worldwide and original equipment for several top class boat builders.
The Cableport is a polished stainless steel entry port that takes electrical and communication cables through the deck via a 49 mm shrouded opening. It can be easily opened to remove cables and connectors when the mast is unstepped or when wiring changes are made. (No silicone or other sealant is required after initial installation).
The Cableport doesn’t catch rigging and lines and can be stepped on without damage. Well worth a look: www.saltyjohn.co.uk