You might as well be up a creek without a paddle if you lose a raft valve in the middle of a wilderness river trip. Unless you carry a spare, that is. You’ll find what you need here: B7 Leafield is a one-way valve used after 1994 in AIRE inflatables.
B7 Leafield Raft Valve. Proven rugged and durable, these two-piece, one-way valves are preferred by quality inflatable manufacturers around the world.