Design Brief & Intent
The Marieholm S-20 was targeted at couples and small families navigating the rock-strewn archipelagos of Scandinavia, where predictable tracking, shallow-draft capability, and heavy-weather protection are paramount. Unlike the motor-sailing models in Marieholm's lineup, the S-20 features an elongated coachroof to prioritize cabin volume, making it a dedicated cruising pocket yacht. Below deck, Enderlein leveraged this extended coachroof to provide up to four full-length berths, a slide-out galley drawer designed for a two-burner stove, and ample storage lockers. The interior is fitted with warm mahogany joinery and molded fiberglass liners that elevate the cabin beyond standard utilitarian "camping" standards. While headroom is limited by its 19.68-foot length overall, the S-20’s cabin feels secure and dry, offering genuine weekend cruising capability for two adults and occasionally small children.
Variations & Configurations
The S-20 belongs to a trio of designs utilizing the same 19.68-foot Olle Enderlein hull. The original iteration, the MS-20 (Motorsailer), featured a massive cockpit, a shorter cabin house, and a small, factory-installed inboard diesel engine (frequently a Volvo Penta MD1). The AC-20 (Aft Cabin) featured a center-cockpit layout and a tiny separate aft cabin. The S-20 (Sail) was engineered as a lighter, sleeker option that deleted the inboard engine option entirely. Instead of carrying a heavy diesel or the alternative concrete ballast block used in motor-sailing versions without engines, the S-20 relies on a transom-mounted outboard motor bracket. This choice saved significant weight, improved under-body drag, and allowed the cockpit floor to be lowered, creating a deeper, more secure helm station despite the smaller overall cockpit footprint necessitated by the longer cabin trunk.
Sailing Performance & Handling
On the water, the S-20 behaves with the deliberate, reassuring motion of a much larger vessel. This stability is largely dictated by a displacement of 2,756 pounds. When paired with a displacement-to-length ratio (Disp/LWL) of 240.95, the S-20 falls squarely into the moderate-to-heavy displacement category for its length. The boat tracks tenaciously and resists the rapid, jerky motions typical of modern, flat-bottomed pocket cruisers. With a comfort ratio of 17.03, it handles chop and coastal ocean swells with ease.
However, this sea-kindliness comes at the cost of light-air agility. The sail area-to-displacement ratio (SA/Disp) of 14.89 indicates that the S-20 can feel underpowered in light breezes, requiring a larger genua or spinnaker to keep moving below 8 knots of wind. A ballast-to-displacement ratio of 28.81%—comprising a 794-pound cast-iron fin keel—provides reliable initial stiffness, allowing the S-20 to carry full sail when other 20-footers are forced to reef. The capsize screening ratio of 2.06 indicates that the boat is best suited for coastal cruising and day-sailing rather than offshore passage-making. At the helm, the fractional rig and skeg-hung rudder provide balanced, predictable control, though the boat's design prioritizes steady, straight-line tracking over snappy, race-course maneuverability.
Known Issues & Triage
Given the age of the Marieholm S-20, several areas require careful inspection prior to purchase. The deck is a balsa-cored sandwich construction. Over decades, hardware such as stanchion bases, cleats, and chainplates can leak, allowing water to penetrate the balsa core. This often results in soft spots on the side decks, particularly around the chainplates and mast step. Triage involves drilling test holes from the interior or using a moisture meter to assess damage; localized recoring with epoxy and high-density foam or plywood is a common DIY fix.
Unlike the encapsulated long keels of earlier Marieholm designs, the S-20 features a cast-iron fin keel bolted to the fiberglass sump. These keel bolts must be examined for crevice corrosion, and the joint itself should be inspected for signs of separation, colloquially known as the "smile." Additionally, because the S-20 utilizes an outboard motor mounted on a transom bracket, owners should inspect the transom laminates. Heavy, modern four-stroke outboards can strain the fiberglass transom, leading to stress cracking or flexing. Reinforcing the backing area with a thick marine plywood or GRP backing plate is highly recommended if upgrading to a heavier outboard.
Modernization & Upgrades
Due to the absence of a bulky inboard engine, the S-20 is an exceptional candidate for modern propulsion conversions. Many owners are choosing to replace noisy, heavy gasoline outboards with clean, lightweight electric outboards (such as Torqeedo or ePropulsion pod and bracket drives). The weight savings on the transom significantly improve the boat's trim and sailing performance in light air.
Another frequent upgrade involves the running rigging. Originally, S-20s were rigged with halyards and control lines adjusted at the mast. Modernizing the deck layout by installing cabin-top organizers, deck organizers, and turning blocks allows all lines to be led aft to the cockpit, making the vessel an incredibly secure single-handed or short-handed cruiser. Finally, replacing the original, leak-prone aluminum-framed windows with new acrylic ports and modern polyurethane sealants is a standard refit task that preserves the interior mahogany from cosmetic water damage.
The Verdict
The Marieholm S-20 is a robust, character-rich pocket cruiser that trades raw light-air speed for reassuring stability and "big boat" sea-kindliness. It remains a highly capable, economical entry point for sailors who value traditional lines, structural integrity, and the design pedigree of Olle Enderlein.
Pros
- Exceptional tracking and comfort in choppy, coastal conditions.
- Highly secure cockpit and robust hull layup compared to contemporary micro-cruisers.
- Expanded cabin trunk offers surprisingly livable interior space and four berths for its size.
- Lack of an inboard engine simplifies mechanical maintenance and eases electric propulsion conversion.
Cons
- Underpowered and sluggish in light winds without a large genua or spinnaker.
- Cockpit space is noticeably smaller than its sister ship, the MS-20, due to the lengthened coachroof.
- Cast-iron fin keel requires regular maintenance to prevent rusting and demands careful inspection of the keel bolts.
