I just watched Episode III recently and I was surprised by what seems to be a plot hole regarding Vader and the speed of spaceships.
The setting
The point in question is when Vader and Kenobi are fighting each other on Mustafar.
As they start fighting, Sidious is on Coruscant and he says something among the lines of "I sense Vader is in danger, let's go help him" and goes.
When we watch the film, it seems rather instinctive that the whole fight is shown on screen, not parts of it.
Then, after a few minutes (on-screen time, not plot-time), Vader is dismembered.
After a few more minutes (on-screen time, not plot-time), Vader is saved by Sidious who just left what seemed to be something like a Theta-class T-2c shuttle (which has a hyperdrive rating of 1).
The base hyperspeed time for Outer Rim to Core planets is 96 hours, according to this chart.
Let's say that you want to go from Tatooine to Alderaan and that you're on a an illegally modified Corellian YT-1300 with a .5 hyperdrive (yep, that one ship), it still takes some time, but let's not reduce it too much and take the arbitrary number of 3 hours since some passengers actually take the time to entertain / train themselves.
It happens that, according to the galaxy map, the route from Coruscant to Mustafar (using the Hydian Way) is about as long as the route from Tatooine to Alderaan (using the Corellian Run).
The question
So... did Vader really survive for, at the very least, 3 hours lying on the verges of a volcano? Ok, he's a boss regarding the Force, but still, he just lost 3 limbs, was slightly cooked, had a "dealbreaker" fight with his lover, and there is no indication that he knows that any rescue is coming. The whole film showed that he was rather mentally unstable (not crazy, just unstable). Yet he had the will to control the Force to survive with all that?
Or maybe was the fight really long?
Notes:
"Legends"-based answers are acceptable since all the base elements used here were written before the canon-reset.