Standard touring Kayaker "Sea to Summit"(buy from any kayak canoeing store) dry bag it is top opening fold over double seal 65 liter is about $55.00-- material similar to the Ortlieb that zipper on the duffel will always leak if the bag goes into or under the water. I had/ have ortlieb cycling panniers that I bought from "Aerostich" they are terrific however I would class the zippers as water repellant rather than waterproof, they leak in heavy downpours.
