Swarm
0.7086°S 130.3055°E · reef
Swarm is a reef dive site in the southern reaches of Raja Ampat, West Papua, Indonesia. The name captures the dominant experience at this site: an overwhelming density of reef fish that fills the water column in moving, shifting masses above and around the coral structure.
Overview
The reef at Swarm is notable for the sheer volume of fish that congregate here. Fusilier schools numbering in the thousands cloud the mid-water, parting and reforming as larger predators pass through. Surgeonfish graze in dense herds across the reef flat, and anthias are so numerous above the coral crest that they are effectively a moving carpet of orange and purple. The combination creates a visual spectacle that lives up to the site’s name.
Below the schooling fish, the reef structure is diverse and well-developed. Hard coral gardens cover the shallower plateau and the slope carries sea fans and encrusting growth to around 25 metres. Whitetip and blacktip reef sharks patrol the deeper edges, and large grouper occupy cave-like shelters in the reef face. The southern position of the site means currents can be variable — when current runs, it energises the schooling behaviour and draws pelagic fish into the mix.
Visibility runs 15–25 metres. Water temperature averages 27–29°C. The site is excellent for wide-angle photography.
Marine Life
- Enormous schools of fusiliers, surgeonfish, and anthias
- Whitetip and blacktip reef sharks on the deeper edges
- Large grouper in reef shelters
- Sea fans on the reef slope
- Occasional pelagics in current
Dive Profile
The dive spends most of its time in the 8–20 metre range, exploring the reef crest and slope while remaining in the heart of the schooling activity. Deeper excursions to 25 metres allow investigation of the shark-patrolled edges. Entry and exit are by boat.
Practical Information
- Depth range: 5–25 m
- Visibility: 15–25 m
- Current: Light to moderate
- Best time: October–April
- Water temperature: 27–29°C
- Entry: Boat
Sources: Papua Diving - Raja Ampat Dive Sites, Bluewater Dive Travel - Raja Ampat Diving, La Galigo Liveaboard - Top 10 Raja Ampat Dive Sites, Girls That Scuba - Scuba Diving Raja Ampat, PADI - Diving in Raja Ampat. Last updated 2026-04-04.
Sea-surface temperature and wave height from Open-Meteo Marine (ERA5 reanalysis, monthly averages).
782 verified species observations (196 species) logged within ~11 km of this site between 1956 and 2016, from the Ocean Biodiversity Information System.
- Eviota nigriventris · Black-spot Pygmy-goby
- Calumia
- Trimma
- Eviota sparsa · Sparse Eviota
- Lomanotus
- Goniobranchus coi
- Notodoris gardineri
- Thecacera
- Chromodoris willani
- Halgerda batangas
- Chelidonura amoena
- Coryphellina exoptata
Scientific survey records skew toward sampled taxa (molluscs, corals) and do not reflect what you are guaranteed to see on a dive.
Source: OBIS (obis.org), aggregated Darwin Core occurrence records.
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