Maybe your inflatable pontoon boat is considered a personal water craft (PWC), like a jet ski or towable inflatable, in which case you need to wear a PFD. You can call someone in the Coast Guard Auxillary and they can answer the question, or call the Coast Guard Boating Safety information line at 1-800-336-BOAT (2628). Hope this helps. Wear the PFD anyhow, just because. Take care!