Westsail 28 is a 35′ 0″ / 10.7 m monohull sailboat designed by Herb David and built by Westsail Corporation between 1975 and 1979.
- Designer
- Herb David
- Builder
- Westsail Corporation
- Association
- Westsail Owners Association
- # Built
- 78
- Hull
- Monohull
- Keel
- Long
- Rudder
- Transom hung
- Construction
- FG solid hull/ply sandwich deck
- Also Known As
- W28
Dimensions
- Length Overall
- 35′ 0″ / 10.7 m
- Length On Deck
- 28′ 2″ / 8.6 m
- Waterline Length
- 23′ 5″ / 7.1 m
- Beam
- 9′ 6″ / 2.9 m
- Draft
- 4′ 3″ / 1.3 m
- Displacement
- 13,500 lb / 6,123 kg
- Ballast
- 4,200 lb / 1,905 kg
Rig and Sails
- Type
- Cutter
- Reported Sail Area
- 475′² / 44.1 m²
- Total Sail Area
- 475′² / 44.2 m²
Mainsail
- Sail Area
- 178′² / 16.5 m²
- P
- 31′ 5″ / 9.6 m
- E
- 11′ 3″ / 3.4 m
- Air Draft
- 39′ 11″ / 12.2 m
Foresail
- Sail Area
- 298′² / 27.6 m²
- I
- 35′ 0″ / 10.7 m
- J
- 16′ 11″ / 5.2 m
- Forestay Length
- 38′ 10″ / 11.9 m
Auxilary Power
- Make
- Volvo
- Model
- MD11HD
- HP
- 13
- Fuel Type
- Diesel
- Fuel Capacity
- 36 gal / 136 l
Accomodations
- Water Capacity
- 79 gal / 299 l
- Holding Tank Capacity
- ?
- Headroom
- ?
- Cabins
- ?
Calculations
- Hull Speed
-
5.9 kn
Classic: 6.49 kn
Hull Speed
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.
Formula
Classic hull speed formula:
Hull Speed = 1.34 x √LWL
A 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
- Sail Area/Displacement
-
13.4
<16: under powered
Sail Area / Displacement Ratio
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.
Formula
SA/D = SA ÷ (D ÷ 64)2/3
- SA: Sail area in square feet, derived by adding the mainsail area to 100% of the foretriangle area (the lateral area above the deck between the mast and the forestay).
- D: Displacement in pounds.
- Ballast/Displacement
-
31.1
<40: less stiff, less powerful
Ballast / Displacement Ratio
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.
Formula
Ballast / Displacement * 100
- Displacement/Length
-
468.8
>400: very heavy
Displacement / Length Ratio
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.
Formula
D/L = (D ÷ 2240) ÷ (0.01 x LWL)³
- D: Displacement of the boat in pounds.
- LWL: Waterline length in feet
- Comfort Ratio
-
38.0
30-40: moderate bluewater cruising boat
Comfort Ratio
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.
Formula
Comfort ratio = D ÷ (.65 x (.7 LWL + .3 LOA) x Beam1.33)
- D: Displacement of the boat in pounds
- LWL: Waterline length in feet
- LOA: Length overall in feet
- Beam: Width of boat at the widest point in feet
- Capsize Screening
-
1.6
<2.0: better suited for ocean passages
Capsize Screening Formula
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.
Formula
CSV = Beam ÷ ³√(D / 64)
- Beam: Width of boat at the widest point in feet
- D: Displacement of the boat in pounds
Notes
From BlueWaterBoats.org:
The Westsail 28 is the smaller sibling to the incredibly successful Westsail 32, a boat that captured the imagination of the American public with the “cruising life”. By the mid in 1970s when demand for the Westsail 32 was in overdrive, the pricing had crept up enough that Westsail needed a new boat to fill the entry spot. The Westsail 28 was launched to fill this in 1975 and was described as “a hearty little offshore cruiser perfectly outfitted for 2 to 3 to cruise trouble free around the world”. The boat made a number of appearances to boat shows along the West Coast and was offered as a complete build ex-factory and later also in kit set form (look for a K in the first 4 digits of the hull number).
Though similar in looks and detailing to the Westsail 32, the smaller boat is a ground up redesign by Herb David and features a number of key improvements. The rig has a taller aspect ratio, the keel is noticeably cut away in the forward sections improving her manoeuvrability, while the garboards are less hollow which help her track closer to the wind.
The resulting boat in comparison to the Westsail 32 is more manoeuvrable with a much more responsive helm and the ride is a tad drier (something the Westsail 32 suffered from). In relation to her size she is faster – expect 110 mile days, but in the wrong seaway she is known to hobbyhorse.
Some of the early boats differ from later ones as design refinements were made while they were rolling out. After the initial six or so boats, 700 pounds was added to the ballast and the total displacement went from 9,500 pounds to 13,500 pounds. With the extra weight the boat sat 4 inches lower in the water bringing the total draft to 4 feet 4 inches. Extra canvas was added to compensate, going from the original 480 sq.ft. to 545 sq.ft. The rudder was also enlarged and around hull number 20 a boomkin was added. In total only 78 boats were produced before the molds were sold in 1979 and shipped to Mexico, a far cry from the 800+ Westsail 32s in existence.
