Una-Una from the dive boat.
This is about diving Una-Una on a day trip from Kadidiri in January 2026. It was the best dive day of that trip, and it was also the day I spent the most time sitting in a boat. Both of those things are worth knowing before you book, so this post covers the diving and the logistics in roughly equal measure.
Una-Una and the volcano
Una-Una is the island in the Togeans with an active volcano, Gunung Colo, which erupted in 1983. From the water you can see dark rock along parts of the shoreline that looks nothing like the green islands around Kadidiri [TODO: verify which areas were affected by the eruption]. I only saw the island from the boat, so I can tell you very little about it on land [TODO: add notes on visiting the island itself].
The volcano was the first thing I could make out on the horizon as we got closer, and for a long stretch of the ride it was the only thing worth looking at. It's a strange shape to have in view while you're kitting up.
Getting out there
I went with a dive centre on Kadidiri [TODO: verify operator name]. The trip ran when enough divers signed up [TODO: verify whether trips run on fixed days or on demand], and I put my name down the day I arrived. We left early [TODO: verify departure time], and the ride out was long [TODO: verify boat time from Kadidiri].
The boat had a canopy over part of the deck, and everyone competed politely for the shade. Bring a hat, a long-sleeved top, reef-safe sun cream and more water than you think you need. I also took a seasickness tablet before we set off, which I would usually skip on a short ride. The sea was flat on the way out and choppier on the way back.
The dives
We did two dives [TODO: verify number of dives per trip and site names]. The first was a wall. I dropped in, went down along it, and the wall carried on below me well past where I was going to follow it. I spent most of the dive looking at the wall itself, which was covered in coral and sponges, and now and then turning round to look out into the blue, where larger fish were moving past [TODO: verify species commonly seen].
The second dive was shallower and more relaxed, along a slope with a lot of fish around the coral heads. I'm not going to pretend I identified everything. My logbook entry for that dive mostly says 'lots', underlined.
Conditions
There was some current on the wall, enough that our guide kept us moving in one direction rather than letting us hang about [TODO: verify typical conditions]. Visibility was good on the day. I'd call it a trip for divers who are comfortable on a wall with a bit of current, not a first dive after a course. The dive centre asked to see my certification card and logbook before they put me on the list [TODO: verify minimum certification].
Lunch and the surface interval
We ate on the boat between dives [TODO: verify whether lunch is included]. I'd have liked to go ashore and look at the old lava up close, but the day didn't allow for it and I didn't push. If seeing the island matters to you, ask before you book whether a landing is possible.
Who I think it suits
For me, the boat ride was worth it. The wall was the best diving I've done in the Togeans. But I'd be lying if I said the boat time was nothing. It's a full day, you come back tired, and on a short trip it costs you a day you could have spent on the reef in front of your bungalow. I'd suggest it if:
- you're a confident diver with at least four or five days in the islands;
- you're based on Kadidiri or somewhere else with a dive centre that runs the trip [TODO: verify which bases offer it];
- you don't mind spending most of a day on a boat.
If you're short on time, or you'd rather stay in shallow water, the reefs around Kadidiri are much closer, and Wahyu covers them in three nights on Kadidiri. Tasya also found quiet snorkelling near Pulau Papan, off Malenge, without a long ride to get there.
Fitting it into a trip
I'd plan the Una-Una trip for the middle of a stay, not the end, for two reasons. First, trips can be called off for weather or numbers, and you want a spare day to try again. Second, the usual guidance is to leave a gap between your last dive and a flight, and the journey from the Togeans to an airport is long enough without that pressure. My post on getting from Ampana to Kadidiri has the boats in the other direction. Work back from your flight and give yourself room.
