I’ve spent hours pumping the bilges of a yacht at anchor off Seil free of gas after some joker left it on. Supper was very late but we didn’t blow the yacht up! Its not very efficient but if you’re at anchor its one way to get rid of the gas. I don’t know about blowing up your airbed/tender but the bellows type pumps are very efficient. I have an Urchin pump on my Wayfarer but generally find a plunger type pump much easier to use though I suppose an Urchin could be rigged with shockcord etc to use singlehanded. My Urchin is permanently plumbed in and I use it mostly for water below the floor boards if its filled on a mooring.