Sectional boat

Also: sectional kayak, sectional canoe, segmented boat

A sectional boat consists of several rigid segments that are plugged together. It's set up in a few minutes.

Wikipedia gives as examples the Pakayak (solo) and the Klepper Backyak (tandem), with about three minutes' setup time. Not all manufacturers count such boats as folding boats. They paddle like hardshells but are considerably bulkier than a packraft.