Loop split between stern and in the rigging (5)
I believe the answer is:
aloft
'in the rigging' is the definition.
I can't judge whether this definition defines the answer.
'loop split between stern' is the wordplay.
'loop split' becomes 'lo' (I can't justify this - if you can you should believe this answer much more).
'between' is an insertion indicator.
'stern' becomes 'aft' (similar in meaning).
'lo' placed within 'aft' is 'ALOFT'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for aloft that I've seen before include "Skyward" , "At a considerable height" , "in a high position" , "Up in the air, high above" , "as 1 ac [PEGASUS] was?" .)