Rod Taylor and Sam Elliot played Travis in Darker Than Amber and The Empty Copper Sea. Neither actor succeeded.
Why?
For one reason Travis is 6’4”, and having a shorter actor just does not make it . ( As this is being written there is a strong rumor that Leonardo DiCaprio will be filming a Travis story. But rumors like this surface every couple of years it seems. Don't pop the corn just yet.
If he were alive and at a right age Sterling Hayden would have fit the bill perfectly. He was 6’5” and had a strong sailing background, and a look at early Hollywood "stills" of him showed he had the looks as well.
Read Hayden's book: The Wanderer and you know what the water meant to him. Very much JDM and Travis.
Oh yeah, one more thing: (from Wikipedia)
Hayden, as OSS agent John Hamilton: his World War II service included running guns through German lines to the Yugoslav partisans and parachuting into fascist Croatia. Hayden, who also participated in the Naples-Foggia campaign and established air crew rescue teams in enemy-occupied territory, became a first lieutenant on September 13, 1944, and a captain on February 14, 1945. He won the Silver Star (for gallantry in action in the Balkans and Mediterranean; "Lt. Hamilton displayed great courage in making hazardous sea voyages in enemy-infested waters and reconnaissance through enemy-held areas"), a Bronze Arrowhead device for parachuting behind enemy lines, and a commendation from Yugoslavia's Marshal Tito. He left active duty on December 24, 1945.[9]
Now, how much more would one want to qualify an actor, and real life hero, to play Travis in the movies??