I use the stock snorkel at the moment, and without the tubes.
I checked pictures of XB and realized they didn´t have snorkel tubes like IX C or IX C/40. I moved the snorkel to the side of the tower and not in front, see picture of U-234:
http://www.coastguardchannel.com/spc...4Schnorkel.jpg
https://encrypted-tbn2.gstatic.com/i...fr_oauCzevVzUw
The stock snorkel is not very nice, combined to Wises and Kovalls snorkel of IX C, but the only one coming close to the one of U-234.
Best regards, Kurfürst