Had the same Problem.
I solved it this way
(of course with help from others)
Create an "invisible H"
tell the boat to go to this point
create an switch/event handler where you set the boat fuel to 0
this switch should be at a point before the boat brakes...
this makes the boat "gliding" to your "invisible H" and then you can use a parachute skript to let the boys disembarke....
which would be another switch/event handler
yes its not easy...
hope i could help
LRSU