Could this be the shape of Ramsey Island?
Here is a picture taken from an old map c1768 by Thomas Jefferys, which shows, maybe, the shape and size of the old Island of Ramsey. It appears to be U shaped, with one arm taking in Bodsey House and going out to almost touch Ramsey Mere. The other arm going out to Worlick House, which did have the Abbey's eel ponds.
The Abbey according to the VCH stood on the highest part of the island some 23ft above the ordnance datum and was reached by a causeway on one side only. The Abbots park stretched away to the east and on the west a town grew up to meet the needs of the Abbey.