Get in after tying up the boat (6)
I believe the answer is:
obtain
'get' is the definition.
(obtaining is a kind of getting)
'in after tying up the boat' is the wordplay.
I cannot quite see how this works, but
'in' is found in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
The remaining letters 'oba' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for obtain that I've seen before include "Acquire or procure" , "'Get, acquire (6)'" , "Get or lay hold of" , "Take possession of" , "Come into possession of" .)