Swimmer of note to the Spanish (3)
I believe the answer is:
eel
'swimmer' is the definition.
(eels swim)
'note to the spanish' is the wordplay.
'note' becomes 'e' (musical note).
'to the spanish' becomes 'el' ('the' in Spanish).
'e'+'el'='EEL'
'of' is the link.
(Other definitions for eel that I've seen before include "Almost scaleless fish" , "Sea creature like conger" , "Long smooth fish" , "Snaky fish" , "Creature like conger or moray" .)