On a percentage basis the merchant marine lost more people than anyone except for the marines. A torpedo to a Liberty ship carrying ammunition simply blew the ship up with no survivors.
Several friends were on the Murmansk run during WWII and went to the lifeboats at least once.
The US Merchant Marine is a fine school but so are the state academies in New York, Maine, Massachusetts, California, Texas, Michigan. Several schools run by the various maritime unions are also world-class.