Captain Nguyen Hong Hai, 57, was detained Sunday as Vietnamese police investigated alleged waterway safety violations after a speedboat overturned near Phu Quoc, killing 15 Indian tourists.
The boat was carrying 32 Indian tourists and four Vietnamese crew members when it flipped less than 0.5 kilometer from shore shortly after leaving Hon May Rut Ngoai island on Saturday afternoon.
Rough seas with waves up to 3 meters hampered rescues; nearby boats and Jet Skis pulled survivors from the water, while some passengers were reported trapped inside the vessel.
Sixteen survivors have been discharged and are returning to India, while one remains in critical condition; the victims' bodies are being moved via Ho Chi Minh City for repatriation.
All 15 victims were on a Lava International company trip, underscoring the risks at a destination serving a fast-growing Indian market that brought about 750,000 visitors to Vietnam in 2025.