Again like many I have fear of 'Open' heights. The first time I flew in a Heli with the door open I was overwhelmed but I knew I had a job to do so had to suck it up.
On fixed wing (even after 20 years) I still get a slight tingle everytime we cross the threshold, I think it's that slight pause as the rate of decent slows right down just before the mains touch,
Low level over a flat calm sea is also a wee bit disconcerting, more of a concern than a fear.
BW