HELLO SCI..CAM.A.PROPULSION is a name given to a propulsion system where the drive unit rides behind the boat transom (weightless) or in a pod allowing the drive to lift straight up for trailering or when an object or the bottom is struck,with a cam like action,unlike an inboard/outboard which has to overcome the propeller thrust or run out of water before they kick back and up.Vessel Pivotal Drive shaft Mounting is the (Patent Title) which gives the ability to build a drive shaft for a boat which can be as basic as was fitted to old boats, or a very sophisticated unit which can be the usual sub-surface 20 degree shaft angle drive,surface drive with surfsce piercing propellers,a kort nozzle steerable or fixed or a shroud and also a jet or turbo drive.There is not just one way to build or any one scale or use for the mounting,it depends on the required use,but when the mounting is fitted all of these drives can be fitted and used..My photo gallery has some images page 6 and 7 showing testing early models and there are other images of a classic boat also fitted with Pivotal Drive.
Great looking boat (and no outboard!)