Island has endless fish, excellent seen from below (8)
I believe the answer is:
sardinia
'island' is the definition.
(Sardinia is an example)
'endless fish excellent seen from below' is the wordplay.
I cannot quite see how this works, but
'fish' could be 'sar' (I've seen this before) and 'sar' is located in the answer.
'from' could be 'in' (I've seen this in other clues) and 'in' is present in the answer.
This may be the basis of clue (or it may be nonsense).
'has' acts as a link.
Can you help me to learn more?
(Other definitions for sardinia that I've seen before include "Island belonging to Italy" , "Second-largest Mediterranean island, after Sicily" , "Adrian is seen in Mediterranean island" , "Large Italian island, capital Cagliari" , "Corsican neighbour" .)