JFK may have been personally brave, but his performance as a combat commander was, to be extremely kind, "unimpressive".
No need to go there -- he volunteered for extremely hazardous duty instead of getting assigned to a more politically advantageous CV or BB. PT boats had about a 20% loss rate, that means statistically you're dead after 10 missions. They zoomed real fast, but had lots of problems.
1. The PT boats were basically plywood fuel tanks filled with high octane gas to feed their powerful engines. Very little armor for crew.
2. PT boats often suffered engine and fuel issues in the humid marine South Pacific environment. Water in the fuel could cause the engines to quit, rust and corrosion meant the crew waged a constant maintenance battle to keep the boat going.
3. Severe torpedo issues that hampered PT boat combat ops.
The Mark 8 torpedo was notoriously bad.
*They used a black powder charge to launch the torpedo out of its tube, and in the wet humid environment that powder could clump or cake, and not fire properly leaving the torpedo in the tube or just plopping into the water.
*That same charge would often produce a pronounced flash f light at night and burst of black smoke that gave away the PT boat's position.
*The gyro sucked and was often thrown out of alignment when the torpedo slapped into the water, so they often wouldn't run true or just dive to the bottom.
*The 500lb warhead wasn't strong enough to outright kill or disable most ships, many skippers reported solid hits on targets that just steamed away.
*Faulty exploders with a 50% failure rate -- that means after all the other issues, half the time you scored a hit the torp wouldn't explode!
*Slow, at just 36kts an IJN DD could just hit the gas and get out of danger.
4. The end of the Line in 1943 -- they were the last Naval units to get supplies and attention. The Battleship Gang felt the PT boats were a novelty gimmick, a expendable stop-gap that would have to make due until the "Real" Navy could get enough fighting ships built and into action.
So their main weapon was crap, they had a 20% fatality rate and they were also last in line for supplies and support.
Brutal.
And then the PT109 got sunk was a total CF that wasn't Kennedy's fault. The guy leading the squadron in an attack on a group of IJN DDs (remember -- the IJN DD has waaayyyy more fire power, is *faster* than crappy US torps, and can take hits the Plywood PT boats can't -- so that's very ballsy!) was ordered by the group commander that he couldn't use radios 'cause the enemy might hear. BUT -- the group commander would send out radio commands in the blind from homebase 40 miles away telling the squadron what to do and where to patrol, with no freaking idea of what was going on 'cause the boats couldn't radio back sitreps.
So the whole thing became a sh&t show. The PT boats quickly got separated at night and lacked the ability to launch a coordinated ambush, and each boat was left to its own devices. Kennedy had crossed the wake phosphoresence of an outbound IJN DD and decide he'd lurk with engines idling near the wake, figuing the DD would come back the same way from its supply run and he'd get a crack at it. Oops, miscalculation, the DD did come back, the PT Boat crew didn't spot it in time on a foggy moonless night -- maybe having been on a combat op for 7 hours already dulled their senses. Anyways, too late, bang!
And when the boat got cut in half and burst into flame, two nearby PT boats saw the explosion, launched hasty torps attacks that failed and zoomed off without checking for survivors with an angry IJN DD nearby -- they reported PT109 lost with all hands.
So no rescue for you, Mr Kennedy! Then what he did to save crew members, what he endured with a fractured spine is crazy heroic. Hauling guys out of the burning wreck, getting them to an island, multiple swims to get more guys, then more swims to get help.
So whatever you think of him as a POTUS, he deserves every recognition for saving his crew after a total sh*t show battle.