Matrosenobergefreiter Alfred Corssen

Hello and good afternoon to you all.

I am seeking information on 2. Kompanie 22. Marinebordflakabteilung
My father, Alfred Corssen was a Matrosenobergefreiter with this company.

I have recieved information from the ICRC which includes POW numbers D766709, 188632 & 070558 ME.
On one of the particulars it states the ship he was captured on was the LANGANGER but having looked at this I can only find that this was a Norwegian Transport Ship so I am struggling to piece together how as a member of the Kriegsmarine he would have been on such a ship?
It says he was captured near Split on the 18.12,1943.
Another mystery is that on a capture card his Erkennungsmarke is 03909/41S but on a document we recieved from the WASt it states the number 059711/42?
This has got me a little confused so any input would be of the greatest help.

Regards
izi