Dots in the ocean (5)
I believe the answer is:
'dots in the ocean' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for isles that I've seen before include "Eyots" , "eg the Scillies" , "eg Fiji and Tonga" , "Hebrides, perhaps" , "Hebrides, for example" .)