Linear banks, probably Medieval or Post Medieval sea defences, located about one kilometre east of Hoo St Werburgh and about 260 metres north of the present bank of the Medway, have been mapped from aerial photographs as part of the English Heritage: Hoo Peninsula Landscape Project. The features appear to protect the seaward side of the Abbots Court moated site (Monument 416813) and are similar to, and possibly associated with, a curvilinear bank (Monument 1547411) which was interpreted, by the excavator of the moated site, as a sea wall dating to the thirteenth century. The sea defences comprise a fragmentary bank 170m long aligned west to east and, perpendicular to it, an irregular bank running towards the south for about 52m and a right angle arrangement of banks with a total length of 102.8m. The earthworks survived until 1963, when the site was destroyed by gravel extraction. Additional sea defences of similar date are located to the south closer to the present bank of the Medway.