There are 2 very common deck/steaming lights. The Forespar light which is the one previonsly mentioned and one by Aqua Signal.
The Forespar unit mounts to the mast with 4 fasteners and the bracket is some what universal to the front of the mast. The body is round and uses a round cap and lens.
The Aqua Signal has a shape that is round in the front and flat against the mast. The mount is 2 fasteners and the plastic flaps must be bent to fit the curve of the mast. To do that you must heat the flaps to make the bend.
You can pick up both replacement lenses at West or others. While doing that as usual replace the bulbs (the deck light is Halogen so don't touch the bulb with your fingers, use a rag).
If the unit needs replacement definetly go with the Forespar. The mounting is far better.
