Warren served as a Merchant Marine during WWII, running pivotal supply routes for the Allies.

Warren enjoyed archaeology and hunting. He studied the Mayan ruins in Mexico, and the Inca ruins in South America. He was a member of the Smithsonian Institute and National Geographic Society.

The United States Merchant Marine provided the greatest sealift in history between the production army at home and the fighting forces scattered around the globe in World War II. The prewar total of 55,000 experienced mariners was increased to over 215,000 through U.S. Maritime Service training programs.

Merchant ships faced danger from submarines, mines, armed raiders and destroyers, aircraft, "kamikaze," and the elements. About 8,300 mariners were killed at sea, 12,000 wounded of whom at least 1,100 died from their wounds, and 663 men and women were taken prisoner. (Total killed estimated 9,300.) Some were blown to death, some incinerated, some drowned, some froze, and some starved. 66 died in prison camps or aboard Japanese ships while being transported to other camps. 31 ships vanished without a trace to a watery grave.

1 in 26 mariners serving aboard merchant ships in World WW II died in the line of duty, suffering a greater percentage of war-related deaths than all other U.S. services. Casualties were kept secret during the War to keep information about their success from the enemy and to attract and keep mariners at sea.

800m swim @ 70-80% effort

50m swim at max effort (sprint)

50m cool down swim at own pace