Why and when?
When will these covers be used? And why were they recommended? Where is the hatch that you want to cover? I thought there was more than one hatch on the H36.It seems like a dodger would suffice for the companionway. If the hatch cover is for privacy and/or shade then install one of those combination shade/screens on the inside.I have a sunbrella cover that I made for my H37C. It covers three of four hatches aft of the mast, the companionway and half of the cockpit including the instruments on the bulkhead and bridgedeck. It has short bungee cords every three feet, the kind with the plastic snap hooks. When I leave the boat I snap it to the toerails. The bimini and a helm cover complete the canvas protection.