Street sellers covering area in vessels (8)
I believe the answer is:
coasters
'street sellers covering' is the definition.
I can't tell whether this definition defines the answer.
'area in vessels' is the wordplay.
'area' becomes 'coast' (I have seen 'seaside area' mean 'coast' so perhaps 'area' could also mean 'coast').
'in vessels' becomes 'ers' (I can't explain this - if you can you should believe this answer much more).
'coast'+'ers'='COASTERS'
Can you help me to learn more?
(Other definitions for coasters that I've seen before include "Small table-mats" , "Small mats for Socrates" , "Merchant ships with a limited range of operation" .)