One way.
On my 37 I use those heavy silver/black covers from West Marine, very strong and very durable. Then I use two long sections of 6" drain hose, one for the bow section, and one for cabin top. I put lengths of 2x3 into them to keep them straight. One goes from mast to pulpit, the other from mast to companionway. These provide enough height to keep the rain water from pooling on the cover. For the cockpit I made a frame from the companionway that sits on the helm. A short curved piece of drain pipe goes from that frame to the coaming. The covers are notched for the mast and overlap about four feet fore and aft. The lines from the grommets go all the way down to the cradle. I do not cover the lifelines so the toerails are exposed at the stanchions. I am mostly concerned about the ports, teak, and cockpit(autohelm, instruments, etc.).
