Studfinder....
not sure of the exact location on an H34, but on the H31 (same basic boat) you can get to the tank. A cheap studfinder from the builder supply store will show you the level of fuel in the tank. A flashlight at the right angle will also do the same thing.OTOH, the Snake River system discussed at length here in the archives, and I think sold at the chandlery is a good system for this particular boat.