MARINE CORPS BASE HAWAII - Retired Navy Capt. Gerald Coffee reenacts a time when he taught a new prisoner how to communicate via tap code while visiting Wounded Warrior Battalion West — Detachment Hawaii, March 27, 2013. Coffee and retired Navy Capt. Jim Hickerson, both former prisoners of war, were invited to speak on the 40th anniversary of their release from Hanoi (Coffee in February 1973, and Hickerson in March of 1973). (U.S. Marine Corps photo by Kristen Wong) - MARINE CORPS BASE HAWAII - Retired Navy Capt. Gerald Coffee reenacts a time when he taught a new prisoner how to communicate via tap code while visiting Wounded Warrior Battalion West — Detachment Hawaii, March 27, 2013. Coffee and retired Navy Capt. Jim Hickerson, both former prisoners of war, were invited to speak on the 40th anniversary of their release from Hanoi (Coffee in February 1973, and Hickerson in March of 1973). (U.S. Marine Corps photo by Kristen Wong)