Hose clamps are evil. They are trying to sink your boat or dash it on the rocks. Don't believe me?
So the hose clamp is just a backup in case the set screws fail. But it has fractured, no doubt due to very small amounts of salt water mist that the shaft seal lets through. A new one is in place, just to the left of the shaft collar.
A tale of two masthead lights. Masthead lights (aka steaming lights) don't sit on the masthead, they are located on the front of your mast and indicate you are under power. Stupid name but that's the COLREGS for you.
1. Remove the two machine screws holding the fixture to the mast
2. Flip over and remove four teeny tiny screws on the back.
3. The front lens then comes apart, into three loose pieces. Which you have to hold into place after removing the bulb and screw back into place.
4. In doing so, you yank the semi-corroded wires from their nuts. No problem, just loosen the nuts and re-attach the wires. However the nut also holds the bulb holder inside the fixture. So when you loosen the nut, the bulb falls inside the fixture. Go back to step 3. Design like this has no place on our boat. So I yanked the evil thing off and replaced it with this:
The new light is a new Aquasignal. It has 1 screw to remove the lens and get at the bulb. Older versions had two. Somebody at Aquasignal knows lights.