The water is wide

Beth's Notes states that The Water is Wide is a Scottish folk song, but has no source.

Wikipedia article states this song is titled "Oh Waly, Waly" and was collected by Cecil Sharp in 1906. I found the arrangement below in Cecil Sharp's Folk Songs from Somerset, Volume 3 (1906). (Click image for full arrangement.) Somerset is a county in England, so I'm not sure where the "Scottish" part of the folk song attribution comes from.

Here is a link to the arrangement by Benjamin Britten. Here is a video with Benjamin Britten accompanying tenor Peter Pears.Peter Pears