Dhonfanu Thila
Depth is the range from the top of the site to its usual maximum; "recommended cert" is the mainstream-agency level operators usually ask for, not a legal rule. Currents and visibility change daily — treat everything here as planning ranges.
Dhonfanu Thila is where Baa's mantas go when they are not feeding in the bay. The pinnacle's coral heads work as cleaning stations through the season, and divers kneeling on the sand perimeter routinely watch two or three animals circle the blocks for an entire dive, wings tipping as wrasse move over their gills. The reef holds its own between passes — morays, sweetlips under the overhangs, turtles on the ledges — but nobody pretends the mantas are not the point. Guides run strict positioning so the animals keep station rather than leaving.
The moment you come for: Season-long manta cleaning activity at kneeling-depth blocks
Topography: Coral pinnacle with cleaning blocks on its flanks and ledges cut into the sides
Current: Plankton-bearing current is what brings the mantas; expect green water on the best days.
Know before you splash
Hazards: Reduced visibility in plankton blooms; multiple boats in season.
Conservation: Stay low, behind the guide's line, and let mantas control every approach.
Nitrox: Worth it here — profiles sit in the range where enriched air meaningfully extends no-stop time (with the training to use it).
Who you'll meet
Giant Moray Eel
Hawksbill Turtle
Oriental Sweetlips
Reef Manta Ray
For photographers
Wide angle: ★★★★★ · Macro: ★★☆☆☆ — editors' 1–5 rating of what this site gives each style of shooting