Commander Everett Alvarez
Was the charactor Lt. Commander Williamson (Michael Moriaty)based on
the real POW Commander Everett Alvarez (USN)?
I believe he was a composite of Alvarez and Jim Stockdale. Oliveira was also based on Alvarez, especially in the scene where the Cuban (whom the POW's called "Fidel") is berating him. Alvarez is Mexican-American and from California, the character of Oliveira was Puerto Rican and from New York, but the situation in the movie fits what I have heard from the POW's I have met.
"It's a hard country, kid."