Design and Construction
The hull is solid fiberglass, with a stub keel and centerboard that give a working draft of around 5.74–6.04 ft, depending on load. Combined with a beam of just over 17 feet and a length-to-beam ratio of 3.75, that shallow draft creates a voluminous hull form with about 936 square feet of wetted surface.
The capsize screening value is 1.62, within the range that the formula alone would admit to offshore-event qualification. An immersion rate of about 3,260 pounds per inch indicates how stubbornly the boat holds her lines as cruising stores come aboard.
Rig, Performance, and Handling
The ketch rig carries roughly 1,895 square feet of sail, for a sail-area-to-displacement ratio of 18.12. On a boat of this displacement, that points to a rig intended to provide carrying power in moderate air rather than outright acceleration.
Calculated maximum speed is about 9.6 knots, while the theoretical displacement-hull speed for her length is 9.8 knots. In other words, the design is intended to cruise near the upper end of its hull-speed envelope rather than surf.
The running rigging reflects the scale of the boat. Estimated jib and genoa sheets are 65 feet long and 5/8-inch in diameter. The mainsheet is more than 162 feet long, while the spinnaker sheet is nearly 143 feet; both also use 5/8-inch line. Those dimensions give a buyer some sense of the loads and long leads involved, whether sailing shorthanded or with a crew.
Accommodations and Tankage
The available record doesn’t describe the interior arrangement in detail beyond the hull’s beamy proportions. The shallow centerboard configuration preserves amidships interior volume that a full keel trunk would consume, while the 950-gallon water capacity supports extended cruising.
Tankage is substantial: 950 gallons of water and 620 gallons of diesel. Together, those capacities mark the Irwin 65/68 as a long-range liveaboard rather than a weekend coastal boat.
The Verdict
The Irwin 65/68 is a purpose-built big-boat cruiser from Ted Irwin’s early-1980s design portfolio: a solid-fiberglass centerboard ketch with the beam and tankage to cross oceans, plus the draft to tuck into shallow harbors. Her numbers describe a stable, load-tolerant hull tuned for passagemaking at hull speed, not a light-air sprinter.
The known documentation focuses on specifications and the scale of the rig rather than potential defects. As a result, the practical ownership picture remains to be confirmed during a survey.
Pros
- Shallow centerboard keel, drawing 5.74–6.04 ft, expands marina and anchorage access.
- Generous beam and tankage—950 gal of water and 620 gal of fuel—suit long-range liveaboard cruising.
- A capsize screening value of 1.62 indicates an offshore-capable hull form by the standard formula.
Cons
- Heavy displacement and a moderate sail-area ratio favor hull-speed cruising over light-air performance.
- Available documentation doesn’t detail the interior layout or structural maintenance history.
