Hello Scarmy,
patience is what you need, With a quote from Dönitz: "endurance and tenacity are rewarded"

. I let the little coasters run, for that they not still chase the whole pack on my neck. I also avoid the destroyers if it is possible in any way and always observe the yellow radio messages and put the Radio Intercepts to a circle of 100 km ( miles? ).
Greetings from Uli
oops , some one was faster...