Theyre left in the vessel and shelter near the end of the bows (4)
I believe the answer is:
lees
'theyre left in the vessel' is the definition.
I can't judge whether this definition defines the answer.
'shelter near the end of the bows' is the wordplay.
'shelter' becomes 'lee' (as in lee side, the side sheltered from wind).
'near the' means one lot of letters go next to another.
'end of' indicates one should take the final letters.
The last letter of 'bows' is 's'.
'lee'+'s'='LEES'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for lees that I've seen before include "Sediment from wine or beer production" , "worst part" , "Dregs of drink" , "Wine at bottom of glass" , "Wine dregs" .)