Only eight boats were built from 1988 onward. That makes the Southerly 135 Mk II a rare, deliberately conceived offshore design rather than a volume-production cruiser.
Design and Construction
The Southerly 135 Mk II measures 44 feet overall, with a 33.92-foot waterline. It displaces 23,100 pounds and carries 9,770 pounds of iron ballast.
The seagoing hull was built to European Union Category A specifications. It was laid up by hand in conventional fiberglass-reinforced plastic, with balsa core in the deck and in the hull above the waterline. At deck compression points where hardware is mounted, plywood infills replace the balsa to concentrate the loads. The vessel also carried a five-year blister warranty.
The defining structural feature is a unique keel box molded integrally with the hull. A 6,260-pound cast-iron grounding plate is fastened to it with twenty-eight 12-millimeter bolts around the plate’s perimeter. The articulating swing keel is a 3,610-pound cast-iron airfoil blade, hinged from the plate on a 2-inch stainless-steel pin running in bronze bushings.
An electric/hydraulic system raises and lowers the keel at the push of a button, with a manual backup. A low-aspect-ratio rudder mounted on a long skeg provides supported steering. The builder also offered a twin-rudder option.
Rig and Handling
The well-considered Seldén masthead rig is paired with a Furlex roller-furling headsail, which testers found easy to handle. An optional tall rig was considered a meaningful advantage in light-air cruising grounds.
Because of the elevated cockpit, the standard boom sits 10 feet above the waterline. Steering is through a Whitlock Mamba bevel-gear torsion-rod system.
In 11- to 14-knot winds, test crews recorded 7.3 knots while close-reaching and 7.5 knots on a beam reach. On a broad reach, boat speed fell by about a knot. One criticism from the same trial was that the Lewmar 48 primary winches felt a little small for a 45-footer.
Power and Systems
Standard power is a 56-horsepower Yanmar diesel driving a shaft. A turbocharged 75-horsepower Yanmar was available as an upgrade; at 2,800 rpm, that engine pushed the boat smoothly at a cruising speed of 7.5 knots.
Tankage is practical and centralized. Two stainless steel water tanks and two stainless steel fuel tanks sit amidships, while two polypropylene waste tanks provide 48 gallons of capacity.
Accommodations and Deck Layout
The raised-deck saloon and high center cockpit define the accommodation plan. The elevated helm provides good visibility, though its position also exposes it to bow spray. A folding dodger helps protect the helmsman while preserving sightlines.
The side decks are narrow and finished with traditional teak, providing secure footing around the boat.
Verdict
The Southerly 135 Mk II is a specialized offshore cruiser for sailors who want shallow-water access without giving up deep-keel performance. Its integrally molded keel box and substantial grounding-plate ballast structure reflect serious bluewater engineering, while the Humphreys hull carries Category A classification.
The raised cockpit and resulting boom height are compromises inherent in the layout rather than flaws. The small primary winches are the one noted handling shortfall. With only eight boats built, however, fleet support and shared owner knowledge are necessarily limited.
Pros
- Variable draft from 2 feet 6 inches to 9 feet 8 inches, using an articulating cast-iron foil keel
- Category A offshore hull with an integrally molded keel box and 28-bolt grounding plate
- Optional 75-horsepower turbocharged Yanmar delivers a 7.5-knot cruising speed
- Twin-rudder version available
- Optional tall rig suited to light-air cruising grounds
Cons
- Lewmar 48 primary winches felt a bit small for the boat’s length in the trial
- High center cockpit and 10-foot boom height leave the cockpit exposed to bow spray
- Only eight were built, limiting fleet support and shared owner knowledge
