I posted some very basic information previously in The Grenadines giving island size and distance to St Vincent. I thought you might like to see the distances. Sorry the pics aren't the best. It was a bit hazy that day. These were all taken from our anchorage between the islands in the Tobago Cays.
The above is looking north towards Canouan.
This view is looking west toward Mayreau.
Here we have Union Island to the south, southwest.
And finally, Palm Island in the foreground and Petit St Vincent and Petite Martinique in the background to the south, southeast.