RIO DE JANEIRO — After clinging to life rafts in high seas for up to 16 hours, more than five dozen students and crew rescued from a Canadian sailing ship that sank in the Atlantic began arriving today in Rio de Janeiro.

The three-masted SV Concordia was on a five-month voyage that allows students in secondary school grades 11 and 12 and the first year of college to study while sailing around the world. The ship sank Thursday afternoon and all 64 people aboard were plucked from the sea early Friday by merchant ships, the Brazilian Navy said.

At least 12 of the rescued docked in Rio at 10:45 a.m. on a Brazilian Navy ship. The rest were to arrive later in the afternoon on two merchant vessels.

The Concordia was caught in high winds and heavy seas when it went down. A navy statement said a distress signal was picked up about 5 p.m. Thursday, and a Brazilian Air Force plane later spotted life rafts in the ocean about 300 miles from Rio.

Forty-eight of those on the vessel were students, said Kate Knight, head of West Island College International of Lunenburg, Nova Scotia, which operates the Class Afloat program.