Upon graduation from College in 1989, Marin set up his own Clinic in Corozal Bay and first served as a doctor there from 1990 to 1994. Prior to 1994, he was appointed Senior doctor which he served until 2007. During his years as a Doctor, Marin never failed to treat his patients whoever they were and his Clinic became one of the most famous and well-known clinics in Belize.