The K-28 is a modified 15 square meter Skerry Cruiser, which is the smallest of the Square Meter classes. Because this design has its rudder separate from the keel, it can not be classed under the Square Meter Rule. The hull form and sail plan dimensions are within the parameters of the rule, so the boat will have the general sailing characteristics of a true 15 square meter.

The whole idea behind the square meters is to get as much speed as possible for a given amount of sail area. A basic hydrodynamic principle is that a longer boat has less resistance than a shorter one at a given speed, all else being equal. The Square Meter Rule penalizes length with increased displacement, beam, and freeboard. However, the square meters are generally very long for the amount of sail area they carry.

In addition to the independent rudder, the K-28 differs from the Square Meter Rule requirements for 15 square meters with a self-bailing cockpit, slightly lighter mast, and lighter construction scantlings. This boat is intended to be sailed in the coastal waters of southern California which is why it is designed with a self bailing cockpit and lifelines. I kept the length at 8.5 meters (28 feet) so the boat could have 18" high lifeline stanchions and still meet ISAF Offshore Special Regulations. 28 feet is short for a 15 square meter, but considering the boat has less sail area than a Cal 20 and is equipped with minimal cruising accommodations, 28 feet is about right. To compensate for the extra weight of minimal cruising gear the K-28 has a few inches more beam and a bit less ballast than I would expect from a typical racing 15 square meter. Following the basic hull dimensions of the Square Meter Rule results in a very small boat for 28 feet, and I would say the K-28 qualifies as a minimalist pocket cruiser.





Hull construction for the K-28 is single skin fiberglass with transverse frames and bulkhead stiffening. A cored hull on such a small boat will have skins that are very thin and subject to damage from impact. The deck is closed cell foam core with fiberglass skins. Scantlings are to ISO 12215-5, "Design Pressures for Monohulls, Design Stresses, Scantlings Determination". The ISO scantling rule is to replace the old ABS scantling rule for offshore racing yachts, so I thought it would be a good idea to start using it with this design.