The Rib is 22 feet long, 8 foot 6 wide, weighs 1.5 tonne and has a draft of nearly 2 1/2 feet. When its on the trailer and the engine is trimmed right down there is only about 2 inches of clearance under the skeg. When recovering the rib by driving onto the trailer it has to be that deep or the engine will strike the ground as the bow lifts on the rear trailer rollers.
The minimum depth it can get recovered in is the top of the wheel rim. At that depth it has to be winched on as the beaching plate at the rear of the hull will sit on the ground even once the rear rollers are under the middle of the boat. Once the plate is on the ground you have to let the winch pull the trailer under the boat until you reach the breakover angle and it drops down.