There are two almost flush openings on the deck with flat covers to close them if desired. They feed to one vent in the cabin overhead, but I was not sure how well they keep the water out and where it drains. I went out and took one cover off to be greeted by a wasp nest the size of my palm and many angry wasps. I grabbed my wasp spray and dispatched many of them. After a while, i got the hose and rinsed off around the vent then let a small stream of water go inside. After a while I saw a small stream of water draining beside the companion way into the cockpit. I tried a little more to see how much the cavity filled up, and it seemed to drain quite well. I think the wasps came in the drain holes, but fortunately didn't find their way into the cabin. I think the dorades may work fine. Because we get late afternoon thundershowers many afternoons and the wind may change direction, I will need to be careful about which way the vent is pointed. Thanks to all who replied.