A boat carrying 80 passengers has capsized in Bali leaving two tourists dead and a third missing.

The speed boat capsized about 5pm AEST after being caught in large surf off Sanur in southeast Bali.

At least five Australians, three men and two women, had boarded the vessel, though local authorities have yet to provide information on their condition.

Denpasar Search and Rescue Agency said 77 passengers survived the incident while two Chinese nationals died and a 23-year-old Indonesian remained missing.

Footage captured the aftermath, where sodden passengers were carried to shore after being rescued from the upturned vessel.