Fisherman's Gat is a much-deepened channel in the North Sea, between the final long line of shoals loosely associated with the Thames Estuary.
In the west it opens onto the nominal cut-off point of Knock Deep (north) or the Princes Channel (south) which links to the Strait of Dover.
The gat in 1934 had minimum depth of 19 feet (5.8 m), naturally greater around its due east access but much less next to the north-west, its narrows/neck.
[2] Shipping generally approaches Fisherman's Gat from an arc, extending from south of Kentish Knock to the far east, around to North East Spit buoy to the south-southeast.
[2] For vessels approaching the Thames Estuary from the south or east, it makes a saving of 20 miles (32 km) and lower pilot charges when compared with the Sunk route to the north.