Design and Construction
The Irwin 30 is built on a solid fiberglass hull, and the American yard offered her with several keel configurations rather than a single fixed arrangement. A stub-and-centerboard variant pairs a fixed stub keel with a board that retracts, letting the boat work both coastal and inland waters; with that appendage the loaded draft runs about 4.3 to 4.6 feet. A fin-keel version draws 3.9 to 4.2 feet, while a third fin option sits deeper at roughly 5.0 to 5.3 feet and still clears most marinas. That spread of underwater profiles is unusual for a 30-footer and tells you the design was meant to serve shallow-draft gunkholers and deeper-keel sailors alike without a new hull mold.
Rig and Handling
The boat is a masthead sloop with a mast roughly 45.5 feet above the waterline and a sail area near 474 square feet. Her standing and running rig dimensions are thoroughly documented: all halyards — mainsail, jib or genoa, and spinnaker — run about 91.8 feet at a 3/8-inch diameter, while sheets for jib, genoa, and mainsheet use 1/2-inch line, the mainsheet itself measuring 75 feet. The cunningham, kicking strap, and clew outhaul are 3/8-inch and run 11 to 22 feet. Those figures place her control lines in the expected range for a 30-foot sloop and imply a straightforward, single-size halyard package that simplifies replacements. The wetted surface of the hull bottom is about 365 square feet, and the immersion rate is near 930 pounds per inch, so she settles predictably under load.
Performance Profile
On paper the Irwin 30 reads as a willing coastal performer. Her theoretical displacement hull speed is 6.9 knots, and the capsize screening value of 1.88 would, by that formula alone, admit her to ocean racing capsize screening value of 1.88. The Motion Comfort Ratio is 25.6, and the displacement-length ratio of 242 puts her among moderate racers rather than heavy voyagers. None of this makes her a bluewater expedition boat by modern standards, but the numbers show a hull tuned for responsiveness over absolute load-carrying.
Known Issues
The Irwin 30's keel-option diversity is the only variation a buyer should note: because the same hull was sold with stub-centerboard, shallow fin, and deeper fin appendages, a given specimen's draft and behavior underfoot must be confirmed from the specific hull rather than assumed from the model name. Sources describe no systemic defects for this model.
The Verdict
The Irwin 30 is a late-1960s Ted Irwin design that reached the market as a 1976 production fiberglass sloop with uncommon keel flexibility for her size. She is a moderate-racer-proportioned coastal boat with documented rig dimensions and a shallow-draft option that broadens where she can be kept.
Pros
- Three keel options including a retractable-centerboard version for thin water
- Solid fiberglass hull with lead ballast and moderate-racer proportions
- Fully documented rigging lengths and diameters simplify upkeep
Cons
- Capsize screening and comfort numbers place her in coastal rather than offshore territory
- Keel-option variation means each boat must be assessed on its own appendage
