Wasn't that Jill Knight , and just the jet ski driver deceased?
I certainly don't want to get in a flame war with the Mast head anchor light Jihadists... but.
No, the light doesn't have to be on top of the mast as some have indicated, even though this is sadly becoming the most common.
At one time ,when we first started cruising ,very few were. Only rich buggers with short masts and lots of steps were. Kerosene lamp was hung anywhere you could reach. The tech at the time was an incandescent bulb , mounted in a Vegemite jar, and hung in the fore triangle each night. The advent of production boats and tri lights certainly make the mast top light an easy solution and permanently mounted one.
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At times it is not the best solution.
You certainly wouldn't mount your Anchor Shape on the mast head , you hoist it in the foretriangle, so why not the light?. Your not protecting yourself from super tankers when anchored in 6 meters of water, just tired yachtsmen arriving late
or drunk dinghy hoons, where some light thrown on deck gives one distance perspective.
Ok Off my soap box.