The theoretical maximum speed that a displacement hull can move efficiently through the water is determined by it's waterline length and displacement. It may be unable to reach this speed if the boat is underpowered or heavily loaded, though it may exceed this speed given enough power. Read more.
Classic hull speed formula:
Hull Speed = 1.34 x √LWLA more accurate formula devised by Dave Gerr in The Propeller Handbook replaces the Speed/Length ratio constant of 1.34 with a calculation based on the Displacement/Length ratio.
Max Speed/Length ratio = 8.26 ÷ Displacement/Length ratio.311
Hull Speed = Max Speed/Length ratio x √LWL
A measure of the power of the sails relative to the weight of the boat. The higher the number, the higher the performance, but the harder the boat will be to handle. This ratio is a "non-dimensional" value that facilitates comparisons between boats of different types and sizes. Read more.
SA/D = SA ÷ (D ÷ 64)2/3
A measure of the stability of a boat's hull that suggests how well a monohull will stand up to its sails. The ballast displacement ratio indicates how much of the weight of a boat is placed for maximum stability against capsizing and is an indicator of stiffness and resistance to capsize.
Ballast / Displacement * 100
A measure of the weight of the boat relative to it's length at the waterline. The higher a boat’s D/L ratio, the more easily it will carry a load and the more comfortable its motion will be. The lower a boat's ratio is, the less power it takes to drive the boat to its nominal hull speed or beyond. Read more.
D/L = (D ÷ 2240) ÷ (0.01 x LWL)³
This ratio assess how quickly and abruptly a boat’s hull reacts to waves in a significant seaway, these being the elements of a boat’s motion most likely to cause seasickness. Read more.
Comfort ratio = D ÷ (.65 x (.7 LWL + .3 LOA) x Beam1.33)
This formula attempts to indicate whether a given boat might be too wide and light to readily right itself after being overturned in extreme conditions. Read more.
CSV = Beam ÷ ³√(D / 64)
The Cape Dory 28 is a rugged little cruiser often quoted as having a feel of a larger boat. She combines traditional looks, quality construction and well-mannered sailing characteristics into a package that is offshore capable. As testimony to her seaworthiness, we’ve seen at least one circumnavigation – in 2009 Fred Bickum completed his three year voyage singlehanded in his 1978 Cape Dory, FêNIX.
At her launch in 1974 the Cape Dory 28 marked the beginning of a fruitful twelve year partnership between Cape Dory Yachts and well respected designer Carl Alberg. Between 1974 and 1987, Cape Dory built 388 in their yard in East Taunton, New England, helping the company forge a grand reputation for producing sailboats that are well constructed with excellent sailing characteristics.
Taking a closer look at her hull shape a trained eye can see much of the classic Alberg form. A Swede himself, he was heavily influenced by the sleek Scandinavian folkboats of the early 20th century, and in that regard the 28’s hull is narrow, making for less accomodation volume belowdecks, but the long overhangs seen in earlier Alberg designs are only hinted at, instead they have been toned down in favour of a longer waterline and gaining back some space. The sheerline is graceful with traditionally low freeboard. Beneath the waterline is a full keel with a forefoot cutaway and ending in a keel-hung rudder which completes her classical profile.
Hulls are of solid fiberglass in polyester resin while decks are balsa or plywood cored fiberglass. The build quality is excellent throughout and the quality of her fittings are good. Bronze is used for the through hull fittings and the eight opening ports, though early boats before 1978 had lower quality plastic ports.
Under sail, they are sea kindly, stiff and capable in heavy seas, yet surprisingly quick in light winds. Nine thousand pounds of displacement, a modified full keel and a well-distributed sail plan results in a well balanced boat that tracks easily, is nimble through the tacks yet has enough momentum to push through choppy water.
In summary, if you’re looking for a small cruiser with classic looks and proven offshore potential, but don’t mind foregoing the interior room seen in more modern 28-footers, the Cape Dory 28 may be a good choice.
» Cape Dory Owners Association’s Cape Dory 28 page. Info, brochures and photos.
» Cruising World Magazine’s review of the Cape Dory 28 by Lauren Anthone, 2007.
» Jack Horner’s review of the Cape Dory 28, BoatUS
Great choice! Your favorites are temporarily saved for this session. Sign in to save them permanently, access them on any device, and receive relevant alerts.