Design and Construction
The Irwin 46 is a solid fiberglass monohull with a keel-and-centerboard configuration, drawing as little as 4.67 feet with the board up and 10.92 feet with it down anchor. That range is the boat's defining trait: owners who cruise shoal venues gain a thin-water runner, while those offshore simply drop the board for a 10-foot-plus profile. Displacement is a substantial 33,000 pounds, of which 12,000 pounds is lead ballast — a 36.36 ballast-to-displacement ratio that, paired with the 277.58 displacement-length ratio, marks her as a heavy, volume-oriented cruiser rather than a light racer. The comfort ratio of 39.87 and a capsize screening figure of 1.68 place her in the stable, ocean-passage-capable band rather than the brisk coastal weekender. Construction is straightforward solid FG in both hull and deck.
Rig and Handling
She carries a staysail ketch rig on a 58-foot mast, with a reported sail area of 858 square feet anchor — modest by performance standards but entirely appropriate to a 33,000-pound cruiser whose motion comfort, not velocity, is the design priority. The ketch arrangement splits the rig into a manageable 517-square-foot foretriangle and a mizzen abaft the helm, letting short crews handle a divided, lower-center-of-effort sail plan. With the centerboard retracted the shoal draft eases tight-quarters maneuvering in anchorages; with it extended the deeper profile steadies her tracking under sail. The 80-horsepower Perkins diesel, burning from a 190-gallon tank, drives a single shaft and gives the displacement hull a relaxed hull speed near 8.2 knots under power.
Accommodations and Tankage
Below, the 46's 13.5-foot beam supports a roomy cruising interior consistent with her 39.87 comfort ratio. The 190-gallon water capacity matches the fuel capacity exactly, a deliberate symmetry that supports long independent stretches at anchor or under way without frequent resupply. The ketch rig's divided sail plan and the centerboard's draft flexibility together make her a plausible liveaboard-and-passage boat rather than a day-sailer stretched to size.
The Verdict
The Irwin 46 is a purpose-built heavy cruiser from the solid-glass era of Ted Irwin's design leadership: a 33,000-pound, keel-and-centerboard ketch whose 4.67-to-10.92-foot draft range and matched 190-gallon fuel and water capacities suit extended cruising in both shoal and offshore venues. Her modest sail plan and high comfort ratio prioritize stable passage-making over speed, and the ketch rig keeps individual sail loads manageable for a short-handed crew.
Pros
- Keel-and-centerboard hull gives 4.67-foot shoal draft and 10.92-foot offshore profile
- 33,000-pound displacement with 12,000-pound lead ballast for stable, comfortable motion
- Staysail ketch rig divides sail loads for short-handed handling
- Matched 190-gallon fuel and water capacity for long independent cruising
Cons
- Sail-area-to-displacement ratio of 13.40 limits light-air performance
- Heavy displacement and 277.58 displacement-length ratio favor passage comfort over agility
