Indonesian rescuers have located all 11 people who were missing after a speedboat capsized in heavy rain off the Mentawai Islands in West Sumatra, bringing the total number of survivors to 18, officials said on Tuesday. The boat overturned at about 11 a.m. local time on Monday while travelling from Sikakap to the nearby town of Tuapejat with 18 people on board, among them 10 local government officials and three children. Seven passengers, including the two crew members, were rescued soon after the accident. Rinto Wardana, an official with the Mentawai search and rescue agency, told Reuters that the remaining passengers survived by swimming for roughly six hours to the nearest island or clinging to debris. Two rescue vessels and dozens of personnel scoured the Sipora Strait overnight before locating the survivors on Tuesday morning. Marine accidents are frequent in the archipelago nation of more than 17,000 islands, where storms and lax safety standards often endanger small vessels. Earlier this month, a ferry sank off Bali with 65 people aboard, killing 18 and leaving 17 missing.