Questions about this sword

[M ELEY]

Here is a sword I have been wondering about for awhile. It seems to have some naval possibilities in my opinion...

[M ELEY]

Note that many naval types have the plain birds-head hilt, ebony grooved grip and stirrup guard. It has a cut-out design of rectangular shape. Blade is single-edged, curved.

[M ELEY]

I have heard of thes sometimes referred to as British NCO's from the 1790s', but for which branch? Any confirmation of this?