WINDSCOOPS
Once you have managed to deflect a lot of glaring hot sun you need to turn your attention to ventilation, and wind scoops are particularly valuable. They are generally made out of lightweight ripstop nylon spinnaker-type cloth and are hoisted from the foreward hatch to face the wind. These work reasonably well as long as the bow is into the wind, though in our experience, they are inclined to chafe around the batten ends in the retaining pockets, which may need reinforcement. There are also versions designed to scoop air from any direction. Getting air to flow through the boat makes a huge difference to life down below, particularly on a hot, still night. They are neither expensive nor bulky to stow, so they more than earn their place on the boat.