If a PT boat hits land it falls through the terrain and alt-f4 is required to get out.
Awesome shot of this happening:
This is what happened after I ran aground at a port:
After ramming a hangar at the port pictured above, I ended up spinning rapidly and rising slowly through the air. Made me think of the WW2OL VTOL 110:)
Warning: cheesy special effect to make it look like it appeared on the screen. I was spinning so fast it looked like I was pointed all directions at once.