I wear a Sgian Dubh only when formally dressed in either Day or Evening styles. By "formally" I mean, with all the accessories. Even then it will be my 'faux' Sgian Dubh - the one with the normal, decorative handle, but with no blade; only a length of flat plastic that goes down inside the hose top.

Long before 9/11, I flew from Aberdeen to London and, as I passed through Security, my real Sgian Dubh was confiscated because, on being measured, the blade was declared to be 3/4" too long ..... it was an offensive weapon!!

I have to say that I have only ever worn that part of 'the outfit' for decorative purposes. In all my life I do not recall ever having the need for a knife when out of the kitchen, dining room, office or garage workshop. As a young lad, like all young lads I had a penknife but I do not recall using it for anything other than sharpening a pencil ..... and we had/have pencil sharpeners to do that!

Plainly, I have no need to carry a knife, which could become a weapon, and so I don't - ever.