Design and Construction
The Irwin measures 45.5 feet overall, with a 13.58-foot beam and a displacement of 26,000 pounds. It carries lead ballast, although sources differ on the exact figure: one gives a range of 7,000 to 8,000 pounds, while another cites a 31% ballast ratio.
The hull and deck are both solid fiberglass. The boat’s seakeeping character comes largely from the combination of a deep forefoot and a shallow fin keel containing the centerboard; Irwin also offered a deeper keel without the board. Owners describe the construction as solid and say the high bulwarks provide a real sense of safety.
Wide side decks and a large, open foredeck make it easy to move around. The shrouds run into the cap rail, leaving the route around the boat unobstructed. The center cockpit lies well abaft the trunk cabin and sits relatively low. Occupants report a gentle motion there, even in high seas.
Rig and Handling
The standard sail plan is a high-aspect cutter rig with twin headstays, although a sloop-rigged version was also built. Owners found that the boat handles any combination of sails well.
The centerboard has a practical role in balancing the boat. By moving the center of lateral resistance fore and aft, the crew can counter the sails’ center of effort. A deeper fixed-keel alternative was also available, giving the two versions quite different helm characteristics on the used market.
Writing in boats.com, one owner said the flared bow rises to the seas and helps keep the deck dry. The boat hobbyhorses a little in rough water, but owners report that the deep forefoot keeps it from pounding. As a sea boat, it is regarded as stiff and quite stable.
Performance Under Power and Sail
The original engine is a 56-hp Perkins 4-154 Series 200 diesel. One owner reported more than 2,000 problem-free hours and described the boat as motoring very well. That owner recorded a cruising speed of 7.1 knots at 2,800 rpm, with fuel consumption of around 1.7 gallons per hour.
Under sail, the Irwin has a capsize screening value of 1.83 and a Motion Comfort Ratio of 32.1. Its displacement-length ratio is 259, placing it among moderate racers, while the sail-area/displacement ratio is 18.64. These figures are consistent with a boat built to cross oceans without punishing its crew.
Accommodations
The interior begins aft with a large master cabin and an en-suite head containing a separate shower compartment. Owners likewise describe it as a big aft cabin with its own head.
Moving forward, over-and-under berths lie to port alongside the cockpit companionway. In the saloon, there is seating to starboard and an L-shaped settee with a dining area to port. The galley is down to starboard beside the companionway; owners praised it as a good, separate galley.
Ahead of the saloon bulkhead, a closed-off forward cabin contains a V-berth and has its own adjacent head and shower. Owners counted three sleeping areas, plus the forward and quarter-berth bunks. In one account, teenagers slept forward and in the quarter berths.
The Verdict
The Irwin 43-CC Mk II is a thoughtfully updated center-cockpit cruiser. Its underwater geometry—a deep forefoot, shallow fin keel, and centerboard—contributes to stable motion and dry decks without pounding. The accommodations are generous and divided for privacy, while the cutter rig and adjustable center of lateral resistance suit short-handed bluewater work. The known record is largely one of owner satisfaction rather than defects.
Pros
- Stiff, stable sea boat, with a flared bow that helps keep the decks dry
- Centerboard allows the crew to balance sail effort by shifting lateral resistance
- Three sleeping zones, with aft master and forward cabins that each have a private head and shower
- Original Perkins diesel reported trouble-free beyond 2,000 hours
Cons
- Hobbyhorses in rough seas, though without pounding
- Deeper fixed-keel alternative gives the two versions quite different helm characteristics on the used market
