Re: Flyin' boats
I don't remember the specifics, but...........
There has been some very large 'objects' that can only fly within a measured distance to the ground because of 'ground effects', the larger air pressure produced between the object and the ground creates enough 'cushion' that the object floats, or has the appearance of flight. Attempts of gaining more altitude loose this air cushion, and the object falls, crashing.
You have seen this ground effect lifting race cars when they get sideways , lifting and blowing the cars over. Boat blow-overs are another example, all is well flying along until a little too much lift, then totally out of control.