Southerly 100 Information, Review, Specs

Sailing Performance & Handling

The sailing characteristics of the Southerly 100 are defined by its variable draft, which ranges from a mere 2 feet 3 inches (0.69m) with the keel up to 5 feet 10 inches (1.78m) when fully deployed. Unlike many contemporary swing-keel boats that rely on a light centerboard for lateral resistance, the Southerly 100 utilizes a heavy, aerofoil-shaped cast iron keel. When lowered, this provides a significant righting moment and allows the boat to point reasonably high into the wind.

David Thomas designed the hull with a relatively fine entry and a flatter run aft compared to the Southerly 105, which improved its off-wind performance and reduced hobby-horsing in a head sea. While it is not a racing yacht, the Southerly 100 is remarkably stiff, largely because a substantial portion of its ballast is carried in the internal grounding plate. This design ensures that even with the keel raised, the boat maintains a safe level of stability, though windward performance is understandably sacrificed. Handling under power is generally predictable, though the single rudder, which is protected by a substantial skeg to allow for beaching, lacks the "bite" of a deep spade rudder in tight marina maneuvers.

Interior Comfort & Variations

The Southerly 100 was marketed as a true deck-saloon cruiser, a layout that provides exceptional light and visibility from the main cabin. This design philosophy allows the crew to monitor their surroundings while seated at the dining table, a feature rarely found in 30-footers of the 1980s. The interior is typically finished in high-quality teak joinery, reflecting Northshore's reputation for premium craftsmanship.

Two primary interior variations were produced during the model's run. The most common "Standard" layout features a linear galley to port and a U-shaped dinette to starboard. An alternative "Gallery" layout was also offered, which modified the seating to accommodate different cruising styles. Both versions utilize the space beneath the cockpit for a dedicated aft cabin, providing a degree of privacy and separation that is highly valued by cruising couples. The raised coachroof provides generous headroom throughout the main saloon, and many hulls were equipped with an internal steering position or "watch-keeping station" at the navigation desk, allowing for comfortable passage-making in inclement weather.

Known Issues & Buyer’s Checklist

Prospective buyers of a Southerly 100 should focus their primary inspection on the keel mechanism, which is the heart of the vessel's utility. While Northshore's engineering is historically robust, decades of immersion require careful scrutiny of specific mechanical components.

• Keel Pennants and Winch: The keel is raised via a stainless steel wire pennant. These cables are subject to fatigue and corrosion; they should be inspected for "meat-hooks" or fraying. The manual or hydraulic winch system requires regular lubrication and should be tested for smooth operation throughout its full range.
• Pivot Pin and Bushings: The keel rotates on a substantial pivot pin. Over time, the bushings can wear, leading to a "thumping" sound when the boat is at anchor or sailing in a sea state. Replacing these bushings often requires the boat to be suspended in a specialized cradle.
• Grounding Plate Corrosion: The external cast-iron grounding plate is prone to surface oxidation. While rarely a structural concern, if the protective epoxy coating is breached, rust can expand and affect the seal between the plate and the GRP hull.
• Window Seals: The large deck-saloon windows are a signature feature but are also a common source of leaks. On older models, the sealant may have perished, necessitating a full "pop-out" and re-bedding of the acrylic or glass panels.
• Rudder Shoe: Because the boat is designed to sit on its keel and a skeg-supported rudder, the "shoe" or bottom bearing of the rudder can take significant stress if the boat is frequently dried out on uneven ground.

Community & Resources

The Southerly 100 benefits from one of the most active owner communities in the United Kingdom and Northern Europe. The Southerly Owners Association is the definitive resource for technical manuals, keel maintenance guides, and historical data regarding hull numbers and original specifications. Owners often share modifications, such as converting manual keel winches to electric or upgrading the original Bukh or Yanmar engines.

The Verdict

The Southerly 100 remains a benchmark for small, versatile cruisers, offering a blend of interior volume and shallow-water capability that few modern boats can match in the sub-35-foot category. While it requires more mechanical vigilance than a fixed-keel yacht, the reward is access to the hidden corners of the coastline.

Pros:

• Versatility: The ability to dry out upright and navigate shallow estuaries.
• Visibility: Excellent natural light and 360-degree views from the saloon.
• Build Quality: Substantial GRP layup and high-grade interior joinery.
• Safety: Stiff sailing characteristics with a high ballast-to-displacement ratio.

Cons:

• Mechanical Complexity: The lifting keel adds a layer of required maintenance and potential failure points.
• Windward Performance: Will not point as high as a deep-fin keel equivalent, especially in light air.
• Rudder Authority: Can be sluggish in reverse due to the skeg-hung configuration.