A small fishing boat overturned Friday off of Ballena in the canton of Osa.
Two U.S. fishermen were dumped into the pacific, said the Servicio Nacional de Guardacostas.
One managed to swim to safety, rescue workers said. The second clung to the overturned craft until help arrived. He was identified as Richard King, 63.
Guardacostas crewmen took him and the towed craft to the coast, said the security ministry.