Replaced ours last April
Going to the boat today and will check the bulb size and get back to you. Ours is a GE bulb with a bayonet type socket. I think the anchor light assembly is a Perko unit that is about 4 in. tall and mounts atop the mast. Think it is the original on our 1982 H36. Had to remove 3 small screws holding the plastic dome-type lens cover. Then, using the slack in the wires, I was able to pull the socket up and out of the assembly to replace the bulb. I had about four tasks to get done that day at the top of the mast and just figured the problem was a burnt bulb. It turned out the bulb was fine and the socket was just corroded a bit. Naturally, I did not bring anything to do an effective job of cleaning the socket. So, it ended up getting fixed in two trips up the mast. The top of the mast made a good worktable but it is a long, long way down if I dropped something. I brought some duct tape with me on the second trip and used it to build a small enclosure on the mast top and keep the parts in while I refurbished the socket. Since one of the screws was a bit rusted, I suspect water was getting in the socket and thus the cause of the corrosion. May be useful to have some sealant handy when reinstalling the lense. Mike s/v Charisma 82 H36
