Protecting arrangement of sails, cross water (8)
I believe the answer is:
irrigate
'water' is the definition.
(I know that water can be written as irrigate)
'protecting arrangement of sails cross' is the wordplay.
'protecting' means one lot of letters goes inside another (inserted letters are held or protected).
'arrangement of sails' becomes 'rig' (I am not sure about this - if you are sure you should believe this answer much more).
'cross' becomes 'irate' (both can mean angry).
'rig' put within 'irate' is 'IRRIGATE'.
Can you help me to learn more?
(Other definitions for irrigate that I've seen before include "Supply land with a constant flow of water" , "Supply water to fields etc" , "Artificially supply land with water" , "Water land to stimulate growth" , "Bring water to (crops)" .)