Marieholm S-20 — Information, Review, Specs

Olle Enderlain·1976 – 1978·~250 hulls·Marieholm Boats
Marieholm S-20 drawingBuilder drawing
Hull type
Monohull · fin
Rig
Fractional Sloop
LOA
19.68' · 6 m
Displ.
2,756 lbs · 1,250 kg
First year
1976

The Marieholm S20, introduced in the mid1970s, represents the "pure sailor" evolution of a versatile 20foot hull platform designed by the legendary Swedish naval architect Olle Enderlein. While Marieholm is perhaps best known for the International Folkboat (IFBoat), the S20 was developed to offer a more voluminous and accessible coastal cruising experience within a compact sixmeter footprint. It was part of a triad of vessels built on the same sturdy, doubleended inspired hull, which included the MS20 (Motor Sailer) and the AC20 (Aft Cabin). Unlike its siblings, which prioritized motoring comfort or cabin separation, the S20 was optimized for traditional sailing, featuring a larger rig and a cleaner deck layout that appealed to those transitioning from smaller dayboats to overnightcapable pocket cruisers.

Measurements

Dimensions 01

LOA
19.68 ft
LWL
17.22 ft
Beam
7.22 ft
Draft
2.95 ft
Max headroom
-
Air draft
-

Construction & hull 02

Construction
Fiberglass
Hull type
Monohull
Keel type
Fin
Rudder
1× Transom-Hung
Ballast
794 lbs (Iron)
Displacement
2756 lbs
Water
-
Fuel
-

Rig & sails 03

Rig type
Fractional Sloop
P · main luff
-
E · main foot
-
I · fore ht.
-
J · fore base
-
Forestay (est)
-
Sail area
183 sqft

Calculations 04

SA/D ratio
14.89
Ballast/Disp.
28.81
D/L ratio
240.95
Comfort ratio
17.03
Capsize screening
2.06
Hull speed
5.56 kn

Sailing Performance & Handling

The Marieholm S-20 is defined by its remarkable stability and "big boat" feel, a direct result of its high ballast ratio. With nearly 45% of its total weight concentrated in the keel, the S-20 remains upright and composed long after lighter 20-footers are forced to reef. The hull features a long, shallow keel that tracks exceptionally well, making it a forgiving choice for solo sailors or beginners. However, this design trade-off means the boat is not a "pointing machine"; its upwind angles are modest compared to modern fin-keel designs, and it requires a stiff breeze to truly come alive.

According to technical specifications archived by the Marieholm Vereniging Nederland, the S-20 carries a sail area that is generous enough for coastal work but is hindered in light air by its heavy displacement—approximately 1,200 to 1,300 kg. In a blow, the boat’s sea-kindliness becomes its greatest asset. It does not slam into chop but rather slices through it, a characteristic inherited from Enderlein's background in designing seaworthy Scandinavian yachts. The transom-mounted rudder provides direct, if somewhat heavy, feedback, ensuring the helm remains manageable even when the boat is pressed.

Interior Comfort & Variations

For a 20-foot vessel, the S-20 offers a surprisingly functional interior, though it remains a "sitting-headroom" boat. The layout typically features a classic V-berth forward and two narrow settee berths in the main cabin, providing sleeping quarters for four in a pinch, though it is realistically suited for a couple. The use of mahogany trim against the white fiberglass hull was a signature Marieholm touch, lending the cabin a warmer, more traditional aesthetic than many of its contemporary French or American counterparts.

The S-20 is the most "open" of the three siblings. The MS-20 (Motor Sailer) variant utilized the same hull but featured a prominent fixed windshield and a different deck mold to accommodate a more sheltered cockpit and an internal steering position. The AC-20 (Aft Cabin) was a rare configuration for a boat of this size, squeezing a tiny separate sleeping compartment behind the cockpit. Because the S-20 lacks these structural additions, it offers the most expansive and ergonomic cockpit for active sail trimming, though it sacrifices the weather protection found on the MS-20.

Known Issues & Buyer’s Checklist

Prospective buyers should focus their inspections on the unique construction methods used by Marieholm in the 1970s. While the hulls are generally considered "bulletproof" solid fiberglass, the decks often utilized a sandwich construction for stiffness.

  • Deck Delamination: Check for soft spots or "crunching" sounds on the side decks and near the mast step, which indicate moisture ingress into the core material.
  • Keel-to-Hull Joint: Although the keel is integrated, the internal ballast can occasionally show signs of "weeping" at the joint if the boat has suffered a hard grounding, a common issue discussed in Swedish owner forums.
  • Rigging and Chainplates: Many S-20s still carry their original 1970s gold-anodized Selden masts. Ensure the chainplates, which are bolted through the hull-deck join, are not showing signs of "bleeding" rust, which suggests internal fatigue.
  • Original Engine Condition: While many S-20s use outboards on a transom bracket, some were fitted with small Volvo Penta inboard diesels. Parts for these vintage engines are increasingly difficult to source, and a repower can easily exceed the market value of the vessel.

Community & Resources

The primary hub for technical data and historical preservation for this model is the Marieholm Vereniging Nederland, which maintains a deep archive of original brochures and modification guides. In Sweden, the Olle Enderlein Shipyard Archive (accessible via DigitaltMuseum) provides digital scans of the original lines and construction plans, offering an invaluable resource for owners performing structural restorations.

The Verdict

The Marieholm S-20 is a quintessential "pocket yacht" that prioritizes safety and traditional aesthetics over raw speed or modern interior volume. It is an ideal vessel for coastal exploration in regions prone to sudden weather changes, offering a level of security rarely found in the sub-25-foot category.

Pros

  • Exceptional stability and seaworthiness for its size.
  • Timely, classic Scandinavian design by Olle Enderlein.
  • Robust build quality capable of handling significant offshore conditions.
  • Active European owner associations provide excellent parts and technical support.

Cons

  • Sluggish performance in light winds (under 8 knots).
  • Limited headroom and cramped quarters for more than two adults.
  • Potential for costly deck core repairs on neglected examples.

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