Design and Construction
Both the hull and deck are of fiberglass, and the interior is finished in teak like most contemporary cruisers. The keel itself is iron rather than lead, a detail that places her in a particular construction tradition for a boat of this size. Her beam-to-length ratio is a moderate 3.39, and the ballast ratio sits at 31 percent, with the recorded ballast of 15,200 pounds against a displacement of 56,000 pounds. The wetted surface of the underwater body is about 667 square feet, a large plane that, combined with the immersion rate of roughly 2,088 pounds per inch, explains why she settles heavily under load and why her draft shifts between 7.22 and 7.52 feet depending on what she carries. That draft keeps her out of all but major marinas.
Rig and Handling
The Nauticat 52 is rigged as a ketch, a configuration that splits the sail plan into manageable pieces for a large hull. Under power she reaches 10.0 knots with her Ford engine, though the theoretical hull speed for a displacement vessel of this length is 8.4 knots, marking the boundary between what the propeller can push and what the physics of the hull allows. The capsize screening value is 1.61, a figure used to argue she could be accepted under that formula's test before the quoted passage was cut. Her Motion Comfort Ratio is 50.6, a number consistent with the easy motion expected of a heavily ballasted cruiser.
Accommodations
Below, the joinery is teak, and the volume follows from a 15-foot beam and a long deck. The interior is like most other boats of the era in being made of teak, which situates her among traditional Finnish-built cruisers rather than spartan racer-cruisers. The layout serves liveaboard and long-passage use, with the volume that a 51.16-foot hull and ultra-heavy cruiser designation imply.
The Verdict
The Nauticat 52 is a purpose-built heavy motorsailer from the Sparkman & Stephens board, produced by Siltala Yachts with a fiberglass hull, iron keel, and ketch rig. She is a marina-limited, load-sensitive passage boat whose documented ratios place her firmly among ultra-heavy cruisers, with a comfort figure and capsize screen that suit offshore intentions.
Pros
- Large, teak-finished interior from a 15-foot beam and 51.16-foot hull
- Ultra-heavy-displacement hull (DL-ratio 378) for stable motion
- Ketch rig divides sail area for manageable handling
- Documented 10-knot powered speed under Ford engine
Cons
- Draft of 7.22–7.52 feet restricts her to major marinas
- Immersion rate of 2,088 lbs/inch shows heavy load sensitivity
- Iron keel rather than lead for those weighing ballast material
