Design and Construction
The Seal 28 has a solid fibreglass hull and a drop keel that raises and lowers vertically. Depending on load, the builder listed her draft at roughly 2.5 to 2.8 feet with the lifting keel.
The iron-ballasted keel weighs 2,900 pounds, while the boat displaces 7,200 pounds, giving a ballast ratio of 40 percent. With a 9.83-foot beam and a length of 28 feet, she has a length-to-beam ratio of 2.82. Her wetted surface is about 258 square feet, and an immersion rate of 952 pounds per inch indicates that she sits heavily for her size.
Rig and Handling
The Seal 28 is a masthead sloop carrying 310 square feet of sail. Her sail-area-to-displacement ratio of 12.21 puts her in the moderate, forgiving band.
The running rigging follows period masthead convention. The jib and genoa sheets are 27.8 feet long and 3/8 inch in diameter; the mainsheet is 69.4 feet long and the same diameter; and the spinnaker sheets are 61.1 feet long rig dimensions.
The lifting keel provides a shallow-draft mode for exploring. Her capsize screening value is 2.04, below the threshold accepted for ocean racing, confirming her role as a coastal cruiser.
Accommodation
Below, the Seal 28 has three cabins and six berths, along with a galley and toilet facility. Fitting that number of berths into 28 feet makes her a genuine pocket cruiser rather than a dayboat with berths added as an afterthought.
Known Issues
The lifting keel is the design’s structural weak point. A vertically raising drop keel requires a trunk, pivot, and sealing arrangement that a fixed-keel boat doesn’t have. On a 28-footer, these are the areas where water intrusion and wear tend to concentrate.
The 258-square-foot wetted surface and immersion rate of 952 pounds per inch also mean that the boat loads deeply when carrying cruising gear. As she works in a seaway, that places stress on the keel trunk and hull-deck joint.
Refits and Ownership
Ownership means maintaining a lifting keel that needs periodic inspection and will likely require rebedding around its trunk. The rig’s sheet lengths are known and reproducible when renewal becomes necessary.
The iron ballast is simple and cheap to live with compared with lead. With only 80 boats built, however, the Seal 28 remains a comparatively rare Primrose design, and good examples are uncommon.
Verdict
The Seal 28 is a thoughtfully proportioned small cruiser with genuine cabin accommodation and a lifting keel that broadens her cruising options. She isn’t an offshore racer, but she is a beamy pocket cruiser with the ballast to feel like a boat.
Pros
- Three cabins and six berths in 28 feet make her a genuine cruiser
- A 40-percent ballast ratio and iron keel provide reassuring stability
- The lifting keel expands her shallow-water capability
Cons
- A capsize screening value of 2.04 excludes her from ocean racing
- The lifting-keel trunk is an inherent maintenance and sealing liability
- Only 80 were built, so good examples are uncommon
