Soft chine kayaks tend to have greater secondary stability and lesser primary stability. Standa This hull type allows boats to move through rough water at higher speeds and they provide a smoother ride than other hull types. HARD CHINE- Having a distinct bottom/side planking junction as opposed to a rounded curve. I give an example here attached, done with "Gene-Hull Sailboat 3.1" : here just two parameters are necessary to input, one to trigger the hard chine line introduction, one to reshape the sections. The hull skin extends above the deck all round to form bulwarks. It has less drag than a flat-bottom boat. DOUBLE CHINE - Having an additional planking junction between the chine and the sheer, giving the hull a more rounded look. Multi-Chine Hull: Boats that feature a multi-chine hull, such as catamarans, are very stable on the water but can be more difficult to maneuver. The multiple chines are simply needed because of the restraint of the flat panels. In the simplest design, the chine is simply a corner on each side of the hull that has no effect on performance or handling. To me a multi-chine hull is one which consists of narrow, flat panels such that the overall effect is that of a shallow arch hull. Multi chines are more complex to build but produce a more seaworthy hull form. Glossary of Boat building Terms The chine is the point where the hull bottom makes a sharp turn upwards to become the side of the boat. Fishform is a term to describe an asymmetrical hull shape that has stern with less volume (narrow) than the bow with greater volume (wide). The multi-chine hull approximates a curved hull form. Multi-hull boats such as catamarans and trimarans more often sport displacement hulls, although there are some that employ planing hulls as well. Multi-chine hulls are vessels 3 or more chines. While mono-hull sailboats typically require a stabilizing weight in the keel, multi-hull boats achieve stability due to the sheer broadness of their profile. Multi-Chine kayaks are somewhere in-between the two. multi chine hull I built a Pygmy Osprey standard kayak with a multi-chine hull. Here you can see the chine on Beneteau's Sense 50 gives the hull a slightly sexier look than a rounded chine would. A rolled chine or round bilge hull form, doesn't have any significant advantage or disadvantage in the stability department (all things being equal). Originally designed as a baby sister to the Sarum 28 for construction in aluminium alloy the multi- chine hull translates easily into plywood and also forms the basis of the Suzanne 81 design. V or arc-bottom chine boats have a V shape between 6 and 23 … Modern hulls on high-speed or rough water vessels might have multiple chine hulls. These can be seen on the hull near the bow. An interesting multi-chine project as a stock boat featuring two different styles, layouts and rigs. Hull form is multi-chine, with the upper chine radiused to give the hull a round bilge appearance when afloat. Fishform Hull. The answer is: The chine aft may help upwind performance a bit but by the looks of the chines we saw in Annapolis, creating hull lines with a more modern and angular look may have been just a important as performance considerations. They are usually displacement hulls. Designers found that by adding a "chine flat" on each side they could increase the lift of the hulls. Multi-hull. MULTI-CHINE - Having one or more additional planking junctions between the chine and the sheer. Stability calculations showed that it would only be possible to provide proper sailing stability for a limited cargo weight range if all ballast was fixed in the keel. Stability is considerably more complex then this, but boiled down to layman's terms, is purely a function of beam and weight location.