Getting through the English Channel

[Corsair]

If you start a career in 1939, there is a moment when you receive a radio message telling you that the Channel is considered closed for german U boats and that Kapt'ns assigned to missions in the Atlantic are to sail across the North Sea. As other above clearly stated, it is strongly advised to follow this order from BdU.
The North Sea being a shallow place and the surroundings of Scapa Flow and the Orkneys being heavily patrolled by DDs and airplanes, I usually hug the Norwegian coast from south of Stavanger to above Bergen and follow the deeper straight north of the Shetlands, staying underwater during daytime and surfaced at night when I hit 200km from the Shetlands where there is an airbase.
There is some traffic there so you might well bag some lone merchants from North of Scotland going down the West Coast and have a good chance of finding convoys even in early war in the western approaches to the north Irish sea entrance (around grid AM 52)
Even with a VIIB, running at ahead standard you have enough fuel to get down to the Bay of Biscay and back. On my present patrol, I am patrolling grid BF47 (with only my 2 external torps left, waiting for nice weather to reload and 35.000 tons in the log on the way down)