M-20 Scow Information, Review, Specs

Sailing Performance & Handling

The M-20 Scow is a pure performance machine that demands active weight management and precise sail trim. Its most defining characteristic is the dual-board and dual-rudder configuration. Because scows are designed to be sailed at a significant angle of heel—often 15 to 25 degrees—the windward rudder and board are lifted out of the water to reduce drag, while the leeward foils provide vertical lift and steerage. The tunnel hull design further enhances this; when heeled, the concave bottom shapes the water flow to act more like a V-hull, which significantly improves tracking and reduces the "skidding" sensation common in flat-bottomed scows.

With a light displacement of approximately 595 pounds and a generous sail plan, the M-20 possesses a high power-to-weight ratio. It transitions to a plane effortlessly, often reaching double-digit speeds in moderate breezes. On the wind, the boat feels lively and responsive, though the dual rudders provide a unique feedback loop—if the boat is not heeled sufficiently, the rudders can feel heavy or "draggy." Conversely, when locked into its design heel, the boat tracks with remarkable "slot-car" precision. According to technical archives from the Inland 20 Class Association, the modern iteration (the I-20) has updated this performance profile by adding an asymmetric spinnaker, which has further boosted its downwind speed and corrected the original M-20’s tendency to be somewhat underpowered in very light air.

Sibling Models & Variations

The M-20 hull has served as the foundation for several variations over the decades. The most significant is the Inland 20 (I-20). While the hull shape is identical to the M-20, the I-20 features a simplified rigging system, a modernized cockpit layout, and the addition of a bowsprit for an asymmetric spinnaker. This evolution was championed by Windward Boatworks to make the boat more accessible and exciting for modern crews.

Other "siblings" in the scow family share the same design DNA but differ in scale. The C-Scow is a 20-foot cat-rigged (single sail) relative that is heavier and more powerful, while the E-Scow is a larger 28-foot variant. Within the M-20 class itself, older hulls were primarily wood, but the transition to fiberglass in the late 1960s standardized the weights and stiffness of the fleet. Owners often distinguish between "legacy" Melges-built M-20s and the newer, more robust builds produced by Windward Boatworks under the Inland 20 banner.

Known Issues & Buyer’s Checklist

Prospective buyers of older M-20 Scows should prioritize hull structural integrity, as these boats were built for speed rather than longevity.

1. Deck-to-Hull Joint: On older fiberglass models, the deck-to-hull bond can weaken over decades of high-tension racing. Inspect the rub rail area for cracking or signs of separation, particularly near the shroud chainplates.
2. Cockpit Floor and Foam Core: Many scows utilize a sandwich construction. If the boat has been stored outside or has had hardware leaks, the internal foam core can become saturated. This "wet foam" issue significantly increases the boat's weight and ruins its competitive edge. Check for soft spots on the cockpit floor and the side tanks.
3. Bailer Leaks: The M-20 uses "auto-bailers" (often DePersia style) located in the hull. These are notorious for leaking if the gaskets are perished or if the housing has been struck by debris.
4. Rudder and Board Trunk Stress: Because the M-20 is sailed heeled, the side-loading on the leeward board trunk and rudder gudgeons is immense. Look for "spiderweb" stress cracks in the gelcoat around the trunk openings and the transom.
5. Mast Step Compression: The high rig tension required to keep the forestay tight can lead to compression of the mast step. Inspect the area under the mast for any sinking or deformation.

Community & Resources

The legacy of the M-20 is currently upheld by the Inland 20 Class Association, which governs racing rules and organizes regional championships. For technical support and new builds, Windward Boatworks remains the primary authority, providing parts, hull repairs, and new I-20 models that keep the 20-foot tunnel-hull design active on the water.

The Verdict

The M-20 Scow is a specialized racing machine that offers a level of speed and tactical complexity rarely found in other 20-footers. It is an ideal choice for lake sailors who enjoy technical "tinkering" and the unique physics of scow racing.

Pros:

• Exceptional planing performance and speed-to-size ratio.
• Unique tunnel-hull design provides a stable, "locked-in" feel when heeled.
• Active secondary market and parts availability through modern class successors.
• Highly technical rig that rewards skilled sail trimmers.

Cons:

• Requires a dedicated and athletic two-person crew to manage heel and sail loads.
• Susceptible to "wet foam" and core delamination in older, poorly maintained hulls.
• Open cockpit design makes it unsuitable for rough, open-water coastal conditions.