DiveTwin
Dive site

Mafia Island

Indian Ocean, Tanzania

Typical depth
25 m
Type
Reef
Level
Intermediate
OPEN WATERSURFACE102030SAFETY STOP · 3–6 mTYPICAL25 m

Notes

Whale shark season Oct–Mar.

Marine life

Rays
manta ray, eagle ray, stingray
Corals
hard coral gardens, sea fans, soft corals
Sharks
whale shark (Oct–Mar aggregation, juveniles), whitetip reef shark, occasional blacktip
Turtles
green, hawksbill
Pelagics
giant trevally, barracuda, tuna, kingfish
Whales & dolphins
humpback whale (Jul–Sep passing), bottlenose dolphin
Reef fish
napoleon wrasse, grouper, snapper, sweetlips, schooling fusiliers

Site features

  • Whale Shark Aggregation
  • Snorkel + Dive
  • Marine Park
  • Channel Drift
  • Reef

When to dive

Best
Oct–Mar
Avoid
Jun–Aug

Mafia Island sits off the Tanzanian coast at the mouth of the Rufiji Delta, where nutrient-rich outflow draws a seasonal aggregation of juvenile whale sharks into Kilindoni Bay Oct–Mar (peak Nov–Feb), surface-feeding on copepod blooms. Chole Bay marine park holds the general reef diving — coral gardens, walls, and channel drifts. NE monsoon (Nov–Mar) brings calm seas and warm water; SE monsoon (Jun–Sep) brings rough crossings and many operators close.

Conditions & access

Visibility
15–30 m
Water temp
25–29 °C
Current
Moderate
Access
Seasonal
Min cert
Open Water; Advanced recommended for the channel drifts

Location

7.8500° S, 39.8500° E

Sources

Curated from 2 sources

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