The wind was taking off in gusts, and the rain was putting down the swells. I made out a patch of beach that looked less like death than the rest of the arena, and I decided to drive in on a gust under the spitfire-sprit -- and, if she answered her helm before she died on us, to humour her a shade to starboard, where the water looked better. I stayed the foremast; set the spritsail fore and aft, as though we were boarding; told Sulinor to have the rudders down directly he cut the cables; waited till a gust came; squared away the sprit, and drove.
(This is from "The Manner of Men" by Kipling.)
I can't understand the meaning of this phrase:
to have the rudders down directly