Design and Construction
BK Marin built the Mamba 29 in solid fiberglass with a fin keel offered in iron or lead. The boat was also sold for home completion, so build quality may vary from one example to another.
The hull carries 3,086 pounds of ballast, giving a ballast ratio of 44 percent—higher than 69 percent of comparable designs. With a beam of 9 feet 7 inches and a length of 28.5 feet, its length-to-beam ratio is 3.04, making it roomier than 54 percent of similar boats.
A displacement-length ratio of 255 places the Mamba 29 among moderate racers. Its capsize screening value is 2.00, which means it would not be accepted in ocean races. That provides a useful boundary marker for a boat whose natural business is sailing in sheltered waters.
Rig, Performance, and Handling
The fractional sloop rig is slightly overrigged, carrying more sail plan than 58 percent of similar sailboats. That bias also appears in the performance ratios. Sail-area-to-displacement ratio is 16.8 with the ISO reference sail, rising to 19.7 with a 135 percent genoa. In that configuration, the boat is faster in light wind than 58 percent of similar designs.
The theoretical hull speed is 6.4 knots, while relative speed performance puts the Mamba 29 ahead of 42 percent of similar boats. Its motion comfort ratio of 21.3 also exceeds that of 42 percent of comparable designs.
An immersion rate of 774 pounds per inch means the boat settles noticeably when loaded. This is relevant because its draft varies from 5.25 to 5.55 feet with burden.
The control lines follow a consistent specification:
- Main, jib, and spinnaker halyards: 101 feet of 5/16-inch line
- Jib and genoa sheets: 29 feet of 3/8-inch line
- Mainsheet: 73 feet of 3/8-inch line
Accommodations and Capacities
The dimensions define the living space. A beamy 3.04 length-to-beam ratio and moderate displacement suggest a compact but usable cabin for a 29-foot design. The 26-gallon water capacity sets a realistic coastal-cruising range.
Engine
The 8-horsepower Yanmar diesel gives a calculated maximum speed under power of 3.8 knots. That is adequate for marina maneuvering rather than passage making.
Known Issues and Ownership
The only documented construction caveat is the home-completion option. Because BK Marin also sold the Mamba 29 as a kit, individual boats may differ in build quality. Although an iron fin keel was available, the cited material includes no corrosion note for that option.
Ownership considerations center on keel choice, original build quality, and rig upkeep. A lead-fin example starts from a higher ballast-quality baseline than an iron-fin hull. The slightly overrigged fractional setup rewards a clean genoa lead and careful halyard maintenance. Because all control lines have specified lengths and diameters, replacement is straightforward.
The Verdict
The Mamba 29 is a coherent small Scandinavian sloop: beamy for its length, stiff for its size, and quick in light air thanks to a slightly overrigged fractional rig. By its capsize-screening figure, it isn’t an offshore boat. As a sheltered-water racer-cruiser, however, it offers a predictable platform, a lead-keel option, and a documented production run—provided a buyer verifies the build quality of any home-completed example.
Pros
- 44 percent ballast ratio, higher than 69 percent of similar designs
- Roomier than 54 percent of comparable boats, with a 3.04 length-to-beam ratio
- Light-air speed ahead of 58 percent of similar designs with a 135 percent genoa
- Lead fin-keel option for durable ballast
Cons
- Capsize screening value of 2.00 excludes it from ocean races
- Home-completion kits mean build quality can vary
- Modest maximum speed under power of 3.8 knots
