Group of islands I spy, alone at sea (9)
I believe the answer is:
polynesia
'group of islands' is the definition.
'polynesia' can be an answer for 'islands' (I've seen this before). I am unsure of the 'group of' bit.
'i spy alone at sea' is the wordplay.
'at sea' indicates anagramming the letters.
'i'+'spy'+'alone'='ispyalone'
'ispyalone' with letters rearranged gives 'POLYNESIA'.
Can you help me to learn more?
(Other definitions for polynesia that I've seen before include "Islands including Hawaii, Tonga, Samoa, etc." , "large group of islands" , "Extensive group of Pacific islands" , "Pacific island group" , "Pacific islands incl. N Zealand, Samoa and Hawaii" .)