Last we went to Kauai. We could see two lighthouses right from the deck of the ship. One was what I think was the Kaua'i - Kuki'i Point minor light at the edge of the golf course
and just a little farther out the Ninini Point Lighthouse
I saw this one on the last day on the way back to Oahu from Kauai
It is clearly a round white tower with a red lantern room and is active, but I haven't been able to figure out which one it is because I'm not exactly sure where the ship was when I saw it.