Hewitt - Hitlers Armada : the German invasion plan, and the defence of Great Britain by the Royal Navy, April - October 1940

Keep then the seas about in special;

Which of England is the round wall,

As though England were likened to a city

And the wall environ were the sea.

Libelle of Englyshe Polycye, 1436

The best method of dealing with a German

invasion of the Island of Britain was to drown

as many as possible on the way over and knock

the others on the head as they crawled ashore.

Winston Churchill to General Maxime Weygand, 11 June 1940

List of Maps

HMS Venomous . During the Dunkirk Evacuation, Venomous rescued 4,140 men, making five trips. In September 1940, she was part of the 18th Destroyer Flotilla, based at Harwich. As a Modified W Class destroyer, she was armed with four 4.7-inch guns, two 2-pdr anti-aircraft guns, and six 21-inch torpedo tubes. She was over twenty-one years old by September 1940 but, in common with her sisters, was still a potent weapon against an invasion fleet without surface escorts. (IWM Neg. No. 56091)

HMS Vimiera . Originally a V Class destroyer, Vimiera had been rebuilt between June 1939 and January 1940 as a Wair anti-aircraft escort vessel. The photographs show the extent of the conversion, which involved the replacement of four low-angle, 4-inch guns by two twin, 4-inch, dual-purpose mountings, the removal of both sets of torpedo tubes and the construction of a new bridge. The unsatisfactory HACS control system for the guns can be seen at the rear of the bridge. The only close-range armament consisted of two sets of the ineffective quadruple .5-inch machine guns. In September 1940, Vimiera , although part of the Rosyth Escort Force, was actually based at Sheerness. (IWM Neg. Nos. FL22801 & FL5533)

Admiral Hipper . During the summer of 1940, Hipper was the only major German warship in operational condition. This pre-war photograph shows her before she was fitted with a funnel cap and a lengthened, raked bow. She was an elegant, powerful warship, hindered by unreliable engines. Her role in Sealion would have been to divert the British Home Fleet away from the landings by operating in the vicinity of Iceland. (IWM Neg. No. HU1009)

Proof of intent? Aerial photographs of Operation Sealion barge concentrations at Dunkirk. By September 1940 the German naval staff had assembled sufficient shipping to transport the invasion force, and, if Sealion had gone ahead, 150 of these barges would have sailed on the afternoon of 20 September 1940, carrying leading elements of the 17th and 35th Infantry Divisions. (IWM Neg. No. C1819)

Similar concentrations of barges at Boulogne. The largest of the invasion fleets, including 330 barges, would have sailed from here with the 26th and 34th Infantry Divisions, to attack the BexhillEastbourne landing area. (IWM Neg. MH6657).

HMS Garth . One of the first Hunt Class escort destroyers to commission, Garth , together with her sister Fernie , was escorting coastal convoy CE9 when the Gris Nez battery fired at them (and missed) on 12 August 1940. Garth was armed with two twin, dual-purpose, 4-inch guns and a four-barrelled, 2-pdr, close-range mounting. In September 1940, she was part of 21st Destroyer Flotilla, at Sheerness. (IWM Neg. No. FL13374)

Two of the motley collection of vessels hastily converted for use as part of the Sealion fleet. The 37mm anti-aircraft gun mounted on the deck of the coaster would have been of little use against a determined attack by Royal Navy destroyers and cruisers. (IWM Neg. Nos. HU72022 & HU72023)

A rare photograph of invasion barges exercising off St Malo. The comparatively crude nature of the modifications carried out to convert these vessels into primitive landing craft can be seen, most particularly the rudimentary ramp cut into the bows which can hardly have improved their already dubious seaworthiness! (IWM Neg. No. HU95927) (Photographs 1 to 10 by kind permission of the Imperial War Museum)

HMS Winchelsea , September 1937. Winchelsea was a W Class destroyer, completed in 1918 and armed with four 4-inch guns. She had taken part in the Dunkirk evacuation and by September 1940 was part of the 11th Destroyer Flotilla of Western Approaches Command, based at Liverpool. Most of the V & W Class destroyers in 193940 would have looked very similar, although some would have had the after set of torpedo tubes removed and replaced by a 12-pdr anti-aircraft gun. This would also have involved removal of the mainmast.