You can't have good patrols all the time can you.
I found that very often patrols that start lousy turn out to be the most rewarding in the end. so be patient!
Just finished my first patrol in my new IXc, in a career from 1939. I have a habit of getting myself sunk on the first patrol in a new boat, but this time I had a problem free patrol. Attacked a convoy and sunk two large cargoes in CF5684, then a large merchant in the BF sector. Too bad it scores no points in the September Ace competition (operation Spinennennetz).