Kerama Islands

There are two ways to dive the Keramas and they make for different trips. Day boats leave Naha early, cross the open channel, fit in two or three dives around Zamami, Aka and Tokashiki, and are back in the city by evening. Staying out on the islands changes the rhythm completely: the village shops run a few minutes to their sites, come back in for lunch, and can add an afternoon or a night dive without anyone facing another crossing.

The topography is gentle and varied rather than dramatic. Shallow bommie fields and table-coral terraces sit on white sand that throws light back up, which is much of why the water reads so pale; the deeper edges fall away into rocky slopes and undercuts where soft coral takes over. The channels between the islands carry enough tidal flow to justify a drift plan and enough structure to hold fish, and guides pick the site on the day from the tide table and the wind.

Turtles are what brings people back, and the two common species behave differently: greens graze shallow flats and seagrass, hawksbills pick at sponges around the coral heads. Both are used to divers, so the technique is to settle onto the sand and stay put rather than swim after them. Night dives from the island bases turn up hunting octopus, parrotfish asleep in their mucus cocoons, and the small animals that daytime dives pass straight over.

It works for mixed groups where half the party only snorkels, and for anyone who wants an easy week rather than a technical one. Conditions rather than marine life set the calendar: April to September is the calm, clear stretch, while winter northeasterlies push swell across the crossing, cancel ferries and shorten the site list without closing the season, and that is also when island boats give much of their time to whale-watching runs. Divers set on big pelagics or deep walls should treat this as a complement to somewhere else.