The Kentish Knock is a long shoal (bank, shallows) in the North Sea east of Essex, England. It is the most easterly of those of the Thames Estuary and its core, which is shallower than 18 feet (5.5 m), extends 6 miles (9.7 km). Thus it is a major hazard to deep-draught navigation. It is exactly 28 miles (45 km) due east of Foulness Point, Essex and is centred about 15 miles (24 km) NNE of North Foreland, Kent – both are extreme points of those counties.