Shortage of nautical gear unknown outside Italy (8)
I believe the answer is:
sparsity
'shortage' is the definition.
(I know that shortage can be written as sparsity)
'nautical gear unknown outside italy' is the wordplay.
'nautical gear' becomes 'spars' (spar can mean a mast on a ship).
'unknown' becomes 'y' (algebra).
'outside' is an insertion indicator.
'italy' becomes 'it'.
'spars'+'y'='sparsy'
'sparsy' placed around 'it' is 'SPARSITY'.
'of' acts as a link.
(Other definitions for sparsity that I've seen before include "Scantiness" , "Thinness of occurrence" , "Thinly-scattered state" , "Low density" , "Shortness of supply" .)