My name is Ferdisha Snagg. I live in Cherry Hill, St. George's Grenada. My grandfather was a Snagg. He passed away in 2002 on his return to Canouan in January of that year. There are a number of Snaggs here in Grenada, including my own family. I know my grandfather was from Canouan. I'm not sure of the details of his heritage but he did explain to us once something we had read in a grenadine boating magazine about his father/grandfather formerly owning the island before they were cheated of it by some JP.
I myself have never been to Canouan but my aunts and mother have.
Hope to hear from you. We must all be one big family I suppose, since Snagg is not a popular surname as far as I know.