Semper Fidel (2014)

In the wake of his estranged father's death, Jim Acosta a U.S. Marine goes to Havana to learn about his father's past. He discovers that his grandfather, Mario, is still alive and the owner of a boxing gym in Havana. Jim convinces Mario to train him and a bond is created that will change Jim's life forever. With the comfort of knowing he is not alone, Jim returns to the States to rejoin his unit.