Regardless of type of vessel; sail, freighter, tanker, or fisherman most of these all-around lights are most conveniently rigged as a hoist. Dredges, pilot boats, and the like who regularly display such lights may have a permanent mounting for them. This usually involves two lights being installed for each light required; that is to say, there is a light on one side of the mast and another directly on the opposite side of the mast, equalling one all-around light. It's not the desire to carry the lights that is the rub, it's the rigging of them.
Note: If you get close enough in to a large sea-going ship you may well no longer see his sidelights or masthead/foremast lights. The navigation lights, especially the sidelights, are mounted in a side light box, which prevents glare from the light, reflecting off the ship, mess up the angle at which another can see the light. These were not designed with the idea of sailboats looking for them whilst close aboard. As tjk indicated, your first indication that you may be in such a night-time situation is that it appears to be black as the earl of hell's riding boots in one direction and normally dim in another. This is known as the "blotting out the horizon" phenomena, and it frequently does not end well.(g) In such situations, sound signals are your only remaining method of attracting attention.
With the advent of led' it's not hard to imagine seeing a ring of lights, that would gird the mast, providing an all-around light. It will probably be made first in Portugal, where they are notoriously scared of the dark, and usually position their navigation lights so as to best illuminate their lost bottle of Muscatel. That's why they put the bow pulpit stanchions in front of the sidelights-greater light coverage of the deck! Portugese sailboats look like floating discos at night for that reason. They should be treated as any other vessel displaying all-around red over red.(G)
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Wm. F. Buckley, Jr.