Are there any B.O.B. books written from zee German's side of the action ?

Salute

Actually, while the Battle of Britain, which was an aerial engagement, was won by the RAF, the existence of the British Navy was at least as important to the fact the Germans could not invade as the presence of the RAF in the skies.

Because the Royal Navy outnumbered and dominated the German navy so thoroughly, in order to have a successful invasion, the Germans needed COMPLETE Air Superiority. The British merely needed a contested air space for their Navy to be able to operate, albeit with considerable loss, against an invasion.

For example, while the Germans had an overall air superiority during the Dunkirk evacuation, the RAF was able to contest control enough so that the Royal Navy could come in and evacuate the BEF. Losses were heavy in ships, but the job was done.

If the Germans had launched their invasion in September 1940, they would not have been able to prevent the Royal Navy from entering the Channel and sinking the majority of the German transports and supporting Naval elements. The losses to the Royal Navy would be high, but considering the alternative was the overrunning of the British homeland, it would be acceptable.

The Royal Navy never participated except in a peripheral way in the Battle of Britain, but when Hitler, the Werhmacht, the Kriegsmarine, and the Luftwaffe, planned their operations, it was the shadow in the corner of the room, the proverbial 1000 lb Gorilla.