Well you can cross it at night....be sure to hag closely the French coast..just off Calais. The waters there are a bit shallower, but most escorts patrolling (in June 1940 GWX that I am, mostly armed trawlers) will not come too close.
Try to pass on the surface at max speed and set your depth at 6.5-7m to conceal your hull and leave only the tower showing. That WILL slow you down, but provide also a very rapid dive to PD (18-22 sec.) and improved stealth...If the seas are rough, you will also get by this method hydrophone detection of any ship that is in your range...
And of course.....pray that you wont be seen by an elco...
And...since you will be in the neighbourhood , try to Inflitrate dover...you may find 50.000+ tons in Feb 1940...
