JFK did more than serve honorably. He served heroically.
JFK wound up in PT boats because he was banging a Danish woman correspondent Hoover believed was a Nazi agent. So JFK was transferred from Naval Intelligence [at the behest of Daddy] to the PT boat school down in the Carolinas. Miss Copenhagen followed, the affair resumed and JFK wound up in the Pacific on [surprise] a PT boat.
His first accomplishment as a skipper [which should have been his last], was to destroy a dock. The incident that made him famous started out with the PT 109 as part of a picket line, with ourders to keep both engines idling and one [or two, I forget which] lookouts. Kennedy only had one engine on, and no lookout, which explains how a slower Japanese destroyer could cut his boat in half.
And yes, his actions after the collision were heroic. But if he’d done his job, they wouldn’t have been necessary, and no injury or loss of life probably wouldn’t have taken place.