Other marine life
Dugong
Dugong dugon
A sirenian — the only strictly marine herbivorous mammal — that grazes seagrass in shallow coastal waters across the Indo-Pacific. It is listed Vulnerable globally on the IUCN Red List; several subpopulations are assessed separately and more severely, with East Africa Critically Endangered and New Caledonia Endangered as of the 2022 assessments. Dugongs are slow-moving, shy of boats and engine noise, and are rarely encountered by scuba divers anywhere.
- Max size
- 3m, up to about 400kg
- Habitat
- Shallow coastal seagrass meadows, usually under 10m
Best places to dive with Dugong
| Month | Likelihood |
|---|---|
| January | rare |
| February | rare |
| March | rare |
| April | rare |
| May | rare |
| June | rare |
| July | rare |
| August | rare |
| September | rare |
| October | rare |
| November | rare |
| December | rare |
A real but scarce seagrass visitor. No month is coded as a peak.
| Month | Likelihood |
|---|---|
| January | rare |
| February | rare |
| March | rare |
| April | rare |
| May | rare |
| June | rare |
| July | rare |
| August | rare |
| September | rare |
| October | rare |
| November | rare |
| December | rare |
A 2024 study compiled only 42 Phu Quoc records over 20 years, mostly from April to December along Ham Ninh and Ong Doi. These are survey and community records across the island, not a realistic scuba-diving encounter rate; do not book Phu Quoc expecting a dugong.
| Month | Likelihood |
|---|---|
| January | not seen |
| February | not seen |
| March | not seen |
| April | not seen |
| May | not seen |
| June | not seen |
| July | not seen |
| August | not seen |
| September | not seen |
| October | not seen |
| November | not seen |
| December | not seen |
Con Dao holds one of Vietnam's last dugong populations, grazing the seagrass beds — but it is close to gone. About twelve animals remained at the 2023 survey, four died in early 2025, and Vietnamese authorities describe the population as facing disappearance without urgent intervention. Divers do not see them: this is a conservation fact about the place, not something to hope for on a dive.
Sources & last checked
Checked August 2026
Research is source-backed, but conditions and fees should still be confirmed locally.
View 3 sources and checking notes
- HCM City eyes urgent solutions to conserve endangered dugong population in Con Dao, VietnamPlus (Vietnam News Agency)
- Con Dao IMMA factsheet, IUCN Marine Mammal Protected Areas Task Force
- IUCN Red List: Dugong Subpopulations Reassessed, Dugong & Seagrass Hub
Note on the data: The Vulnerable listing is the global assessment. Regional subpopulations carry separate, higher-risk listings, and Vietnam's animals are not covered by a published subpopulation assessment.