I just bought a used 9' Avon inflatable, and I'm a newcomer to all of this. After inflating each tube with the manual foot pump, the seller explained that I need to first cover my hand over the hole and then quickly put the cap on as the air is escaping.
Shouldn't there be a check valve here? This seems unsafe should the cap come loose when underway.

If a check valve is needed, is it simply missing?

Thank you

Ken, I had a 10 ft avon years ago. The value proberly should have a flapper in the opening to keep air from
getting out. If not you will have to get a new one or just hold your hand over the valve till you replace the valve cover or buy a new valve.

Richard