Wrecked hull on U-boat (not British) docking at port (8)
I believe the answer is:
honolulu
'port' is the definition.
(Hawaiian port)
'wrecked hull on u-boat' is the wordplay.
'wrecked' indicates anagramming the letters.
'on' indicates putting letters inside (as in clothing 'on' a person).
'u' becomes 'ono' (I can't explain this - if you can you should give a lot more credence to this answer).
'boat' becomes 'u'.
'hull' is an anagram of 'hlul'.
'hlul' placed around 'ono' is 'honolul'.
'honolul'+'u'='HONOLULU'
'not british docking at' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for honolulu that I've seen before include "Hawaii's capital" , "American port" , "US Pacific state capital" , "Hawaiian city" , "Hawaiian capital" .)