MP 31 Information, Review, Specs

History and Design

The creation of the MP 31 falls within Länsivene Oy's operational period (1978-2004), a company founded by the Tätilä brothers, Osmo, Onni, and Atso, in Rauma Unaja, Finland. The shipyard distinguished itself by employing a "cross-laminate" wooden strip technique for its MP sailboats, often utilizing mahogany veneer, which contributed significantly to the strength and longevity of their hulls.

Naval architect Matti Pulli was the visionary behind the entire MP sailboat series, imbuing his designs with structural integrity and durability. The MP 31, built with a wood hull and deck, exemplifies this ethos of robust construction. While the primary production run for the MP 31 concluded in 1984, an interesting variation emerged in 1989. An updated version, known as the MP 315, was constructed from GRP (Glass Reinforced Plastic). Only one MP 315 was ever produced, featuring a slightly increased length overall (9.7m / 31.82ft) due to a tilted transom and a masthead rig, departing from the original's fractional setup.

Sailing Performance and Handling

The MP 31, with a length overall of 31.0 feet and a waterline length of 24.61 feet, presents an interesting profile in terms of performance metrics. Its calculated Sail Area to Displacement (SA/D) ratio stands at approximately 20.29, suggesting good potential for performance in lighter air conditions.

However, the Displacement to Length (D/L) ratio, calculated from the provided specifications, is quite high at approximately 444.19, which would typically indicate a very heavy, traditional cruiser. This figure appears to be in contrast with some qualitative descriptions found in external sources, which characterize the MP 31 as a "light sailboat" and a "high performer," with one source reporting a significantly lower D/L of 198.10. This discrepancy may arise from different measurement methodologies or specific loading conditions.

Regarding stability, while the precise ballast weight is not consistently available, with one external source reporting a ballast-to-displacement ratio of 0%, this figure is highly unusual for a fin-keeled monohull and likely indicates missing data rather than an actual absence of ballast. Despite this, the MP 31 is described as "reasonably stable / stiff," though with a "low righting capability if capsized." Equipped with a fin keel and spade rudder, the boat offers enhanced maneuverability, albeit potentially at the cost of some directional stability compared to vessels with full keels. Overall, the MP 31 is often considered best suited as a day sailer or weekender.