Nudibranch

Abundant and varied across the walls and muck; Cave Point and the muck sites are particularly good, and rare species such as the Djibouti giant nudibranch have been recorded.

Ambon is known as much for nudibranch diversity as for its frogfish, with species turning up across the bay slopes, the jetty pilings and the outer walls year-round.

Anilao is one of the richest nudibranch areas on earth, with hundreds of species documented; found year-round on nearly every macro dive.

The Dili-coast shore sites — Tasi Tolu, Dili Rock East and the sand side of K41 — are macro dives, and nudibranchs are a standing feature of them year-round rather than a seasonal one.

Peer-reviewed surveys recorded high sea-slug diversity across Bangka habitats, but individual species vary by site and season.

Nudibranchs are reported as one of the standing macro subjects on the wrecks, alongside whip-coral crabs and shrimp. Species composition is not documented in the sources used here.

The walls and slopes hold a wide variety of nudibranchs; Bunaken Timur and the Siladen reefs are good for macro-focused dives.

The deeper zones at Hon Cau's Shark Fin site are specifically described as nudibranch-rich. Macro is the realistic strength of Con Dao diving, given the shortage of large animals.

Nudibranchs are found on the coral-covered hulls, especially the Kogyo Maru, for divers who slow down and look. Year-round.

A huge variety of nudibranchs, including Costasiella (Shaun the Sheep), are found across the Dauin muck year-round; a mainstay of macro-focused dives here.

Common on the reef and muck sites around San Miguel Island and Ticao, which are noted for macro photography.

Reliable for macro fans across the reefs and on night dives at Meno Wall; a range of species present year-round.

Nudibranchs are common macro subjects across the reefs and on the wreck structure.

Common across the soft-coral pinnacles and macro sites year-round.

The most reliable thing to look at here. Nudibranchs are found year-round on the shallow rocky reefs off Koh Rong and Koh Rong Sanloem, with one site named for them.

A steady macro subject across the reefs; many species present year-round, popular on training and photography dives.

Year-round, and the southern upwelling sites are where they concentrate — Cannibal Rock, Yellow Wall and the Nusa Kode bays are described by operators as holding unusual nudibranchs alongside fire urchins, sea apples and Coleman shrimp. Wainilu in the central park is the accessible muck alternative from a day boat. No seasonality documented.

Hundreds of nudibranch species are recorded in the strait; found on every dive year-round.

Diverse nudibranchs year-round across Gato and the macro sites.

A range of Mediterranean nudibranch species on reefs and wrecks; the artificial-reef wrecks at Xatt l-Ahmar are known for them. Resident year-round, a macro-photography staple.

Abundant macro subject on the walls and house reefs, especially Tongo Point and the Panagsama wall.

The most consistent thing in the water here. Guides routinely find a dozen or more species on a single dive at Moray Beach and Electric Nose. Present year-round with no meaningful seasonality reported.

Diverse nudibranchs and flatworms year-round, best found on night dives. The Spanish dancer (Hexabranchus sanguineus) is among the notable Red Sea species.

Good variety on the channel walls at Ceningan and on the shallow plateaus, though Nusa Penida is a big-animal destination first — for serious macro, Lembeh or Amed are better use of the time.

Panglao is a strong macro region — nudibranchs are reliably found year-round on the Arco Point wall, the Danao and Momo slopes and the Doljo reef. Numbers and variety depend heavily on the guide.

The strongest part of the region's macro. Terumbu Tiga, Terumbu Dua, Cina Terjun at Redang and the wrecks all hold good numbers year-round in season. Rubble and dead coral from the 2024 bleaching event has, if anything, increased the algae and hydroid growth some species feed on.

A wide range of nudibranchs is present year-round across the reefs, a staple of the region's macro diving.

Nudibranchs are one of Phu Quoc's more credible draws, especially on northern macro sites. Species and density vary, with no supported seasonal peak.

Dozens of nudibranch species are reliably found across Puerto Galera's macro and muck sites year-round; a core draw for critter hunters.

A year-round macro subject on house reefs and sheltered slopes; this dataset category groups multiple nudibranch species.

Resident year-round across most reef and rubble sites; one of the most consistently found macro subjects in the region.

Nudibranchs and sacoglossan sea slugs are the core draw. Melibe colemani and Cyerce nigra are documented by name, but neither a particular species nor a rare individual is guaranteed.

Diverse nudibranchs year-round on the Mabul and Kapalai muck sites (not subject to the November closure).

Nudibranchs are a realistic macro subject on sheltered reefs and wreck structure throughout the operating season.

Nudibranchs are found on Tioman's boulder reefs and night dives throughout the operating season; species composition varies.

Vava'u's macro is a genuine strength: nudibranchs are reliable on the cave walls and at Split Rock and Sea Fans, year-round.

A wide variety of nudibranchs are found across the reefs year-round, a staple for macro shooters here.

Nudibranchs occur on Kona reefs, but this broad group has no useful monthly calendar.

Nudibranchs occur on island reefs with no defensible seasonal calendar.

A grouped macro category reported on house reefs and sheltered slopes; individual species and year-round detectability are not independently established.

Nudibranchs occur on Oʻahu reefs and wreck growth, with no useful month-level trend.

Multiple nudibranch species occur on wreck growth and reef substrate. This order-level record does not imply a predictable species or season.

Nudibranchs occur on sheltered reefs and night dives. No meaningful archipelago-wide seasonality is published.