I've criused the globe in a Type XXI, there is some traffic around out side of the KM Grid's but its few an far between. However, IF u hang around an area long enough, traffic increases. I haven't tried a Type IX boat so I cant say if you will make it. All I can say is, Stop often at any friendly port and good luck.
Penag was a nice sleepy lil sea side port and the women and wine went down well. Made for a pleasant change from the snow bunny's in Norway !!