
Mesali Island Reef
Pemba Island · Tanzania
The fringing reef around uninhabited Mesali Island is among the most intact coral ecosystems in the western Indian Ocean, its shallows crowded with hard corals in colours that look digitally enhanced: iridescent greens, deep purples, and chalky yellows. The reef slopes gently from the beach to 20 m and the diversity is staggering — over 300 fish species recorded here including species rarely seen on more trafficked reefs. Octopus roam the rubble zones and pipefish drift vertically between sea grass blades at the reef edge. The whole site has a dreamy, unhurried quality because you may be the only divers here for the entire day. Mesali is the Pemba secret that Pemba itself does not yet know it has!
Conditions
Depth
3 to 22 m
Open water and up
Current
Usually still
Can pick up on the edge
Visibility
18 to 30 m
Clearest in the calm season
Water
23 to 30°C
5 mm full suit
Month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water (°C) | 27 | 27 | 28 | 28 | 26 | 24 | 23 | 23 | 24 | 25 | 26 | 27 |
| Vis (m) | 12 | 12 | 10 | 8 | 10 | 15 | 18 | 18 | 15 | 15 | 12 | 12 |
| Current | Gentle | Gentle | Still | Gentle | Gentle | Gentle | Still | Still | Still | Gentle | Gentle | Gentle |
Your chances of seeing each animal
Spiny Cushion Star
Last confirmed May 1, 2026 · 15 records
Likely
About 6 in 10 dives
Day Octopus
Last confirmed Mar 9, 2025 · 1 records
Likely
About 6 in 10 dives
Moorish Idol
Last confirmed May 1, 2025 · 3 records
Likely
About 6 in 10 dives
Ocypode celadon
Last confirmed Apr 24, 2025 · 2 records
Sometimes
About 1 in 3 dives
Red-Knobbed Sea Star
Last confirmed Apr 30, 2026 · 12 records
Sometimes
About 1 in 3 dives
Collector Urchin
Last confirmed Apr 23, 2026 · 10 records
Sometimes
About 1 in 3 dives
Staghorn Coral
Expected
Known here, not yet in recent logs
Robust Ghost Pipefish
Expected
Known here, not yet in recent logs
Gear