The sandbank lying in the middle of fairway between the Welsh and English grounds. Described in 19th century Sailing Directions as '... a strip of shoal ground lying throughout its length parallel to Welsh hook, about 2 1/2 cables there from, and 3 cables distance northward of the channel fairway between the English grounds and the Welsh hook in the approach to King Road. The western extreme of this shoal lies Grounds lightvessel... the Middle grounds thence extends in an easterly direction for a distance of about 2 3/4 miles, or to a position with Welsh hook elbow buoy bearing E 1/4 S, distant about 2 miles, and Cleveden pier head S by E 3/4 E. The breadth of the western portion, with depths in some parts of 3 to 4 fathoms at low water springs, is about 4 cables; the shoalest part, extending at half a mile to 1 1/2 miles from the western extreme, is about 4 cables in breadth, with depths of 8 to 12 feet on it; the shoal then decreases in breadth to one cable with sounds of 2 3/4, 3 1/2 dn 4 1/2 fathoms at its eastern edge.'

Sources include:
Admiralty; 1884, Sailing Directions for the Bristol Channel, 4th Ed, pg145-6
Historic Admiralty Chart 2862-A10, RCAHMW Digital Collections sourced from the UK Hydrographic Office and published in 1860

Maritime Officer, RCAHMW, September 2014.