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Sailboat Specifications

Irwin 28 Mk Iv

Masthead Sloop · Fin With Rudder On Skeg

Designed by Ted Irwin · Built by Irwin Yachts · First built 1976

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LOA 28.42 ft  ·  Beam 9.00 ft  ·  Displacement 7,800.00 lb  ·  Sail Area 377.00 ft²  ·  Masthead Sloop  ·  Fin With Rudder On Skeg
About the Irwin 28 Mk Iv Sailboat

Built during Irwin Yachts' active production years, this 28-footer represents the company's continued refinement of their popular mid-size cruising sailboat line. The Mark IV designation indicates this was the fourth iteration of the design, suggesting ongoing improvements based on owner feedback and changing market demands. Irwin sailboats earned a solid reputation for offering good value in the cruising market, typically featuring spacious interiors relative to their length and practical layouts suited for coastal exploration and weekend adventures. The company's Florida-based construction focused on creating boats that balanced affordability with seaworthiness, making them attractive to sailors seeking their first cruising sailboat or those wanting reliable transportation for near-shore sailing. Like other Irwin models from this era, the 28 Mark IV likely emphasized interior volume and creature comforts over pure performance, making it well-suited for coastal cruising and extended weekends aboard. The evolutionary nature of the Mark IV suggests lessons learned from earlier versions were incorporated, potentially addressing any shortcomings in the original design while maintaining the practical appeal that made Irwin a recognizable name in the cruising sailboat market.

Dimensions & Specifications
LOA (Length Overall) 28.42 ft / 8.66 m
LWL (Waterline Length) 23.00 ft / 7.01 m
Beam 9.00 ft / 2.74 m
Max Draft 4.50 ft / 1.37 m
Displacement 7,800.00 lb / 3,538 kg
Ballast 3,200.00 lb / 1,451 kg
Sail Area (Reported) 377.00 ft² / 35.02 m²
Design & Construction
Hull Type Fin with rudder on skeg
Rigging Type Masthead Sloop
Construction FG
Designer Ted Irwin
Builder Irwin Yachts
First Built 1976
Last Built 1981
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Frequently Asked Questions

What is the Irwin 28 Mk Iv's sail area to displacement ratio?

The Irwin 28 Mk Iv has a Sail Area to Displacement ratio (SA/D) of 15.39. Values between 14–18 are typical cruising sailboats; 18–22 is cruiser/racer; over 22 is performance racing.

What is the Irwin 28 Mk Iv's comfort ratio?

The Irwin 28 Mk Iv has a Ted Brewer Comfort Ratio of 26.22. A ratio over 30 indicates good offshore comfort; over 40 is very comfortable offshore.

Is the Irwin 28 Mk Iv safe for offshore sailing?

The Irwin 28 Mk Iv has a Capsize Screening Formula value of 1.82. Values under 2.0 are considered acceptable for offshore sailing; under 1.8 is ideal.

What is the hull speed of the Irwin 28 Mk Iv?

The theoretical hull speed of the Irwin 28 Mk Iv is 6.43 knots, calculated from its waterline length.

How much does a Irwin 28 Mk Iv weigh?

The Irwin 28 Mk Iv has a displacement of 7,800.00 lb and a length overall (LOA) of 28.42 ft.

Who designed the Irwin 28 Mk Iv?

The Irwin 28 Mk Iv was designed by Ted Irwin, first built in 1976.