"Investigation revealed that the said dragon boat team was having their practice when sudden strong waves hit them which caused [their boat] to capsize," spokesman for the Philippine Coast Guard Armand Balilo said, as quoted by the Rappler media portal.
Half of the survivors were women, including one from Russian and one from China, according to the news outlet.
In August, at least 31 people were killed as three motorboats capsized in the Guimaras Strait off the central Philippines.