Electrical connections under deck stepped mast

[Tmacmi]

How is electrical equipment connected through the deck? Is there just a hole or is there typically a plug? I am considering replacing my mast head wind instruments.

I'd prefer not to take off my mast because.

1) I don't want to get into re-tuning the rig
2) I am certain this will be a pandora's box (as all things boat related are)

[AKA-None]

Mine exit the mast and connect to a waterproof socket mounted on the deck in an out of the way location

[chrisr]

most i believe take the cables through the deck to a junction box under-deck. various sorts of deck fittings keep out varying amounts of water

we have a swan neck fitting which never causes any trouble, although it does enter into a drained locker.

cheers,