I can't decide if my gimbal is a degree or two out or if what I'm percieving as that is in fact lens distortion or just an optical illusion due to angle of shots.

The distant horizon looks fairly normal. There's a monument on a hill and it seems upright. But nearer stuff below looks skewed? What do you think?

Video - seems most evident at the water treatment place

Find a water horizon or a building with strong verticals for checking.

It appears to be hills in the foreground. The landscape in the background looks level. I do sequences on the coast and see the same effect in the foreground.

Thanks for the answers, reassuring to hear dak, great tip about the water labroides. Much appreciated guys.

Great video, thank you for sharing. Nice use of composition.