Inflatable Boat

Overview

A rigid-inflatable boat (RIB) pairs a solid molded hull with an inflatable tube collar around its top edge. The hull gives the boat its shape, planing surface and the stiffness to mount an outboard, while the buoyant collar supplies most of the reserve buoyancy, keeps the deck dry by deflecting spray, and acts as a soft fender along the gunwale. The result is a craft that handles like a hard boat under power yet is stable, light, and hard to swamp. This boat seats four and is rated for an outboard up to 30 hp on its transom; the engine itself is not part of the boat as supplied.

The boat is built around the Fiberglass Hull, a hand-laid GRP V-bottom stiffened by stringers and closed at the stern by a reinforced transom. Bonded to the top edge of the hull is the Inflatable Tube Collar, the multi-chamber CSM collar that gives the boat its buoyancy and fendering. The cockpit sole is the Air Floor & Keel, a high-pressure drop-stitch air deck with an inflatable keel, and crew sit on the Seating bench. Around the perimeter the Deck Hardware carries grab lines, D-rings and the bow ring; the Oar Set and Drain & Bailer complete the working fit-out, and an Accessory Kit ships the pump, repair kit and carry bag.

How it works

The collar is divided into independent chambers so that a single puncture cannot sink the boat: each is inflated through a Boston valve, a one-way spring valve that lets air in under the foot pump and seals when the pump is removed. The crew inflate the tube to about 0.25 bar, then pump up the drop-stitch floor and the inflatable keel to a much higher pressure, which tensions the panel into a rigid sole and gives the underside its planing V. Loads from the outboard pass through the motor mount pad into the plywood-cored transom and out along the hull stringers, so the soft collar never carries drive thrust. Underway, the V-hull lifts onto the plane while the tubes ride just above the waterline, knocking down spray and adding righting stability when the boat heels. Water shipped over the bow drains aft to the self-bailer, which opens at speed and closes at rest; the drain plug seals the hull when the boat is ashore. With the tubes deflated, the floor rolled and the whole boat packed into its carry bag, a RIB of this size stows in a car boot.