Later activities on ship are unaffected (7)
I believe the answer is:
artless
'unaffected' is the definition.
(I've seen this before)
'later activities on ship' is the wordplay.
'activities' is an anagram indicator (I've seen 'activity' mean this (letters become active)).
'on' says to put letters next to each other.
'ship' becomes 'SS' (prefix in ship names eg SS Great Britain).
'later' is an anagram of 'artle'.
'artle'+'ss'='ARTLESS'
'are' acts as a link.
(Other definitions for artless that I've seen before include "Without guile or affectation" , "Ingenuous" , "Simple, unaffected" , "Simple and natural in manner" , "Without pretension" .)