The structural remains of the timber section of the First World War boom defence between Grain and Sheerness to protect the Medway from naval attack. The boom was stretched between Grain Tower (NMR monument: 418676) and Garrison Point on Sheerness. Between Grain Tower and the mainland of the Isle of Grain a wooden pier-like structure was constructed to protect the area exposed at low tide. This part of the boom could still be seen centred at TQ 8972 7608 on RAF aerial photographs taken in 1942. Extending between TQ 8933 7605 and TQ 9002 7596 it runs just to the north and parallel to the hard from the beach to Grain Tower, before turning south-east at the tower, again following the course of the hard beyond the tower. The structure has since been removed, but the eroded stumps of its posts can still be seen in the mud at low tide. The chain for the main boom still remains wrapped around Grain Tower. The wooden section of the boom was mapped from aerial photographs as part of the English Heritage: Hoo Peninsula Landscape Project. (1)

<1> RAF, 1942, NMR RAF/26/UK 920 32 23-MAR-1942 (Photograph). SKE55967.

<2> Historic England, Archive Material (Archive). SKE58369.