Born in Cuba, Marin grew up near Oriental Park in Havana and was introduced to the sport at 16. He first worked as a groom and exercise rider and became an agent for Fernando Fernandez, who died one day before him, from 1935-53.

Marin also handled the books of Alvaro Pineda, Walter Guerra and most recently Jorge Velasquez for part of the Santa Anita meet last year. Marin was inducted into the Oriental Park Hall of Fame at Calder Race Course in Miami in 1985.