According to local authorities, a strong storm caused the boat carrying 14 people to sink on Sunday afternoon in Guanabara Bay, in the Atlantic Ocean.
Emergency teams recovered six bodies. Another six passengers survived and two are still missing, including a three-year-old boy, said Leandro Monteiro, commander of the Rio de Janeiro Fire Department.
Divers from the Fire Department searched for the missing with the help of helicopters and jet skis.
The boat had reportedly been hired by families for a leisurely afternoon sailing in Guanabara Bay.