Failed to find sea surrounding island close to Rhodes (6)
I believe the answer is:
missed
'failed' is the definition.
(missing is a kind of failing)
'sea surrounding island close to rhodes' is the wordplay.
'sea' becomes 'med' (abbreviation of Mediterranean).
'surrounding' is an insertion indicator.
'island' becomes 'is'.
'close to' says to take the final letters (the close/ending of).
The last letter of 'rhodes' is 's'.
'is'+'s'='iss'
'med' going around 'iss' is 'MISSED'.
'to find' is the link.
(Other definitions for missed that I've seen before include "Omitted" , "Didn't catch" , "Failed to perceive" , "Avoided" , "came too late" .)