Design Brief & Intent
Designed during an era when fiberglass was rapidly emerging as the dominant production material, the Alumaat 28 was built to offer an indestructible, low-maintenance alternative to wood and composite hulls. Van de Stadt and the Huisman yard chose AlMg4.5Mn, a high-grade, seawater-resistant aluminum alloy, for its superior strength-to-weight ratio and resilience to impacts. The hull features a multi-chine design that reflects the era's metal-shaping techniques, presenting a sharp, narrow profile. With a beam of only 7.87 feet, the boat is remarkably slender compared to modern pocket cruisers, featuring a classic, needle-like hull that minimizes resistance.
The interior of the Alumaat 28 is compact but displays the exceptional joinery and solid construction that would later define Royal Huisman’s superyachts. Wood finishes are clean and functional, prioritized around safety at sea rather than expansive dockside entertaining. It was built for sailors who appreciated structural integrity above all else, designed primarily for coastal cruising, offshore passages, and navigating challenging northern European waters.
Sailing Performance & Handling
The Alumaat 28 is a stiff, sea-kindly yacht characterized by conservative design choices. Its ballast-to-displacement ratio of 47.26 percent is exceptionally high, meaning nearly half of the boat's 3,616-pound displacement is concentrated in its fin keel. This creates a high degree of initial stability and a reassuring righting moment when the wind rises.
A displacement-to-length ratio of 166.34 places the boat in the light-to-moderate displacement category, allowing it to move easily through the water. However, with a sail-area-to-displacement ratio of 14.6, the yacht is somewhat under-canvased by contemporary standards. In light air, it requires a larger head sail or genoa to keep moving, though the masthead sloop rig is simple, robust, and keeps the heeling forces manageable when the breeze freshens.
At the helm, the spade rudder provides excellent responsiveness, but the narrow beam and short waterline mean it lacks the directional tracking of a full-keeled yacht. The capsize screening ratio of 2.05 is technically just over the traditional limit of 2.0 used for ocean racing, which is a consequence of the boat's narrow beam rather than a lack of stability. In a seaway, its comfort ratio of 15.42 reflects a motion comfort profile typical of a light, sub-30-foot vintage boat—meaning it will feel lively and quick in chop, though its deep ballast ensures a safe, predictable return to center.
Known Issues & Galvanic Triage
Because the Alumaat 28 is built from aluminum, its primary structural vulnerability is not rot or osmosis, but galvanic corrosion. Aluminum is a highly active metal on the galvanic scale, and any direct contact with noble metals like stainless steel or bronze in a saltwater environment will cause rapid localized pitting and structural degradation.
A thorough inspection of any Alumaat 28 must focus on galvanic triage. Over five decades of ownership, many of these boats have been subjected to improper hardware additions. Original chainplates, bow rollers, and track fasteners must be checked to ensure they are isolated from the aluminum deck with non-conductive washers or delrin sleeves.
The electrical system is another critical area. A proper aluminum yacht requires a fully isolated, two-wire DC electrical system where the hull is never used as a ground. Standard marine rewiring projects on these boats must ensure that no stray current finds a path to the aluminum hull, which can destroy the metal around the drive shaft or through-hulls in a matter of weeks. The installation of sacrificial zinc or aluminum anodes is mandatory and must be monitored closely.
Market Snapshot & Legacy
With only a tiny handful of hulls completed in the late 1960s, the Alumaat 28 is an exceptionally rare find on the brokerage market. It rarely trades hands, and when a hull does appear, it is typically in Northern Europe. Rather than competing on price with mass-produced fiberglass boats of its size, the Alumaat 28 commands a premium among collectors of classic Dutch yachts, aluminum enthusiasts, and purists who value its connection to the legacy of Royal Huisman.
Prospective buyers must look at the economics of the boat through a long-term lens. While the aluminum hull itself is virtually immune to aging and structural fatigue if protected from electrolysis, a full refit of an Alumaat 28—including modern two-part polyurethane paint, a complete electrical overhaul, and replacing vintage standing rigging—can easily exceed the market value of the vessel. However, for the right owner, preserving a piece of superyacht pedigree is worth the investment.
The Verdict
The Alumaat 28 is a rare, virtually indestructible pocket cruiser built to a standard of craftsmanship that is rarely seen in boats of this size. It is not a roomy family cruiser, but it is an incredibly tough, highly stable classic that stands as a testament to the early genius of Royal Huisman and E. G. van de Stadt.
Pros:
- Built by the legendary Royal Huisman shipyard with superyacht-grade aluminum engineering.
- Highly durable hull material resistant to impacts and completely immune to fiberglass osmosis.
- High ballast ratio offers outstanding stability and stiffness in heavy weather.
- Clean, classic lines and historic pedigree make it a highly respected head-turner in any marina.
Cons:
- Extremely vulnerable to galvanic corrosion and electrolysis if electrical systems or isolating barriers are neglected.
- Narrow beam results in limited interior volume and storage capacity compared to modern designs.
- Under-canvased for light-wind regions, requiring larger head sails to maintain speed.
- Extreme scarcity makes finding spare parts, original documentation, or an available hull highly difficult.
