Two sailboats carrying humanitarian aid from Mexico to Cuba have been located and their crews are safe, authorities and activists said on Saturday, after days of searching for the missing vessels . The boats left Isla Mujeres, in the Mexican state of Quintana Roo, last week and were bound for Havana. The vessels were transporting aid to the Caribbean's island nation, amid biting shortages triggered by a tightened US embargo. They were due to arrive in Havana on Tuesday or Wednesday but failed