Biscuits etc seen aboard ship a good deal (6)
I believe the answer is:
stacks
'good deal' is the definition.
(thesaurus)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for stacks that I've seen before include "Ricks" , "Orderly heaps as of hay" , "Tons" , "bags?" , "A lot (of hay?)" .)