Comoros · Mozambique Channel

Mitsamiouli

Dry-season months generally provide the best local access and visibility.

Mitsamiouli on Grande Comore in the Comoros is a frontier diving destination — volcanic walls, coelacanths (in deep water, beyond recreational range), and reefs barely visited. Infrastructure is minimal.

Good season

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

May–November is dry season. Cyclone risk December–April.

Trip duration

5–7 nights from one of a small handful of resorts.

Dive style

Boat diving on volcanic walls; some current.

Dive level

Advanced recommended.

Reef health

What you’ll actually find
Mixed

Some loss since the 2010s, but the reef still has plenty to dive. Pick depth and shoulder-season carefully.

Coral reef health

How is this calculated?
A decade ago
Survey 2014
33%
Today
Survey 2024
27%

On current trend, no live coral by ~2069. Losing about 0.6% cover per year — roughly 45 years of reef left to see if nothing changes.

Heat stress right now

No stress

No abnormal heat right now. Corals stay coloured.

NOAA Coral Reef Watch · updated May 2026 · 0 °C-week heat dose

What to expect on a dive

Volcanic island reef with limited monitoring data. Anecdotal reports describe declining cover.

Sources, methodology, and the raw numbers

Raw observed numbers

  • Coral cover: 27% (survey Sep 2024, GCRMN Western Indian Ocean transect)
  • Bleached: 16%
  • Recent mortality: 6%
  • East Africa — observed condition reflects the thinning regional pattern.

Raw thermal numbers

  • NOAA CRW alert level: No stress
  • Degree Heating Weeks: 0 °C-wk
  • SST anomaly: +0.7 °C

How we summarise this

Observed coral cover, bleaching, and mortality come from named in-situ surveys with a stated date and method — they describe one snapshot of one reef and do not extrapolate to neighbouring sites. Current thermal stress is satellite-derived from NOAA Coral Reef Watch at ~5 km resolution; it indicates risk, not observed coral damage. We deliberately separate observed condition, current thermal stress, and projection — and we never publish a projection without a documented model and uncertainty.

Sources

Reef condition changes year to year. If you visit, consider supporting responsible-travel and conservation operators on the ground.

Pressure on this reef

Protection · fishing · what you can do

Protected-area status

Multi-use MPA

Inside a designated MPA that permits regulated fishing and other uses. Worth checking which zones at this location are no-take.

Fishing pressure

High fishing pressure

Dominant pressures

  • industrial fishing
  • small-scale overfishing
  • limited enforcement
  • warming

1 Green Fins-verified operator known at this location.

What you can do

Indian Ocean / East African coast has formal MPAs on paper but enforcement is patchy. Tip local guides directly; support community-conservancy diving where available.

Protection status sourced from Protected Planet / WDPA and refined with Marine Protection Atlas. Fishing pressure proxy is Global Fishing Watch AIS data. See the methodology for what these sources can and can’t prove.

Dive sites here

0 curated

Dive sites for this location are still being curated.

We’re working through our top destinations first. Check back soon, or browse the globe for areas with sites already mapped.

Gear

What to bring

Basic kit

What divers say

The Comoros is the unknown corner of the Indian Ocean. Going for the rarity, not the comfort.
Adventure diver