Barshaker... your description of "barn-storming" antics along the sea wall shocked me... because I would personally consider a wall a structure (and the manouevre not a little bit "risky")... but I got to thinking what if you did the same thing on a footpath rather than a wall?
I concluded, yes its complicated; but I'm not sure that MSD regulations are really meant to either permit or prevent such manoueuvres... I have several stories of fatal accidents where people simply "popped up" unexpectedly in deserted/issolated locations.
Anyone want to comment on this?