Dymchurch Seawall: High Knocke to Chapel Road (MU18/7 to 18/9)

The southern end of the Dymchurch seawall is a high embankment faced by a sloping masonry apron, with an asphaltic concrete pavement and a low rear "return wall" with a crest level of about 6.9mOD. The landward face of the embankment is grassed. The wall is old and the apron and the asphaltic surface are extensively patched. The coping stones are concreted in. Over much of the frontage these stones have been displaced by wave action and replaced with a concrete capping beam.
Sand levels along this frontage are relatively stable but the width of the foreshore, between high and low water of medium tides reduces from 350m at the southern end to 250m at the northern end of the frontage.

The field of timber groynes extend from the St Mary's Bay frontage northwards to Marshland Basin, although they appear to have little impact on drift. Beyond that the foreshore is ungroyned, but appears relatively stable. A drop in upper beach levels at the Marshland Basin outfall, and at the two slipways to the north, indicate northward littoral drift on the upper foreshore.

North of the slipway opposite Martello Tower 24 the beach at the apron toe becomes lower. To the south of the slipway there is a typically small shingle fillet. The foreshore is gullied and there are evidently strong littoral currents in this area. The risk of green water overtopping is low. However, the concave shape of the upper part of the concrete apron is conducive to waves being thrown upwards and spray being blown landwards. The low rear wall is too low to be effective, except for preventing the landward flow for water across the surface of the promenade.