Also to point out that those shipboard lights are high pressure sodium lights, which take 3 minutes to restrike when the power is interrupted. Cheap iron core and superimposed pulse starters will not strike a hot tube, until it has cooled down a little, when it will restrike, in about 3 minutes. I would also say the ship owners would also not buy dual tube lamps, where they have 2 arc tubes in parallel in the glass envelope, and which will, if there is a single power dip, have the other tube light up and run, as these cost double the price of the cheap Chinese Ya Ming lamps they likely buy by the case lot. The lights going out is a good indication of power loss, but the relight shows the hot restrike time, and they all coming on nearly at the same time says they were all from the same batch, and all had similar running hours on them, as the restrike time varies greatly with age, and from batch to batch. The only way to have hot restrike is to buy more expensive ballasts that can provide the 5kV plus needed to strike the tube, which needs the wiring to be insulated to the socket, and the socket to be rated for 5kV without flashing over, plus the tubes need a different E40 base design with a wider glass insulator.
No LED lights, the power supplies fail badly, even those designed for rough service use, and do not mix well with salt water ingress, while the magnetic will carry on till the core rots away. Also easy to relamp, as all you need to carry up in a small sling bag is a spare lamp, a new ignitor, a can of WD40 for the rusted fasteners, and some pliers and screwdrivers to open the fixture, which mostly use simple spring clips to allow tool less lamp changes. LED you have to use a rope and pulley to first lower the old one down, and then pull the new one up, and need 2 people up there, and 2 on deck, to do this. Lamp just needs one person and possibly a deck watcher for the crew of 3, doing 3 at a time in an area. Plus also 5 minutes per lamp, excluding the climb, and power does not have to be cut either.