We took the "cruise" at about 1:00pm, maybe slightly earlier. We were lucky in that we had an absolutely perfect weather day. If the weather is not perfect, you will essentially be wasting your time. The boat that you take the cruise on is relatively small. As long as the ocean is calm, you can enjoy the cruise. Yes, the islands and the cave were lovely. But the main problem is, as so often happens in Japan, that during the entire length of the cruise (about 20 minutes) there was a recorded voiceover describing every single thing we were going to see. The voice was a over-the-top cheerful Japanese woman's voice. The Japanese seem to enjoy this kind of "cheerful" voice, but if you are a Westerner, it will grate on your nerves. If you take this cruise, try to be the first people in line to get on the boat. There are only two places that you can view the islands and cave from: the back of the boat (on the open deck) or sitting inside in the covered section -- you don't want to to do that. Just get there early for whichever cruise you're going to take, get to the back of the boat, put on your life jacket and off you go. The little cruise is run well, and the multitude of staff make sure you get on and off the boat with ease. They also wipe everything down (a plus? or minus? of the Covid era) for the next travelers. It was hard to take great pictures, because there were two people standing up the entire time with their selfie sticks basically blocking everything. I don't know if this cruiseline offers "private" options, but if they do, take them -- but only if they turn off the narration, otherwise the experience will be ruined for you.

Amazing cruise looking at the rocky cliffs around the coast and of course going into the cave and looking up the hole Try to get a good seat!