Design Brief & Intent
The core mission of the Portsmouth 48 is to deliver unwavering offshore security and exceptional liveability for short-handed cruising couples. Ted Hood designed this hull to slide through heavy seas without the jarring motion typical of modern flat-bottomed cruisers. The interior reflects this classic offshore philosophy: hand-fitted woodwork, deep fiddles, secure handholds at every transition, and a spacious salon that remains comfortable whether at anchor or on a 15-degree heel.
Compared to other builds from Hood’s design office—such as his Little Harbor series—the Portsmouth 48 prioritizes massive mechanical propulsion capability. While a standard 48-foot auxiliary sailboat of this vintage might carry a 75-horsepower engine, the Portsmouth 48 was engineered around a formidable 315-horsepower Yanmar diesel. This hybrid identity positions the boat firmly in the elite class of high-performance motorsailers, rivaling the liveaboard utility of dedicated trawlers while maintaining a functional masthead sloop rig.
Sailing Performance & Handling
Under sail, the Portsmouth 48 behaves with the steady, predictable manners of a classic displacement cruiser. With a sail area-to-displacement ratio of 15.8, the sail plan is conservatively sized, emphasizing ease of handling and safety over light-air speed. It is not a boat that will ghost along in a five-knot breeze; instead, it comes alive when the wind freshens, utilizing its heavy displacement to punch through chop with minimal loss of momentum.
The boat’s displacement-to-length ratio of 190.33 indicates a moderate displacement profile that balances load-carrying ability with respectable hull speed. A ballast-to-displacement ratio of 28.65 percent, paired with a heavy lead keel, provides a stiff righting moment. At the helm, the full-keel configuration delivers superb directional stability, allowing the boat to track straight for hours with minimal autopilot effort.
The comfort ratio of 32.6 translates to a gentle, slow-rolling motion in a seaway, reducing crew fatigue on multi-day passages. This sea-keeping quality is paired with a capsize screening value of 1.84. This is well below the industry-standard threshold of 2.0, mathematically verifying the vessel’s high resistance to capsize and cementing its status as an ocean-ready passagmaker.
When the wind dies or turns directly on the nose, the Portsmouth 48 transitions into a highly efficient power cruiser. The 315-horsepower Yanmar engine easily drives the hull past its theoretical displacement speed, allowing owners to maintain tight cruise schedules regardless of the weather.
Variations & Configurations
Designed as a dedicated long-range cruiser, the Portsmouth 48 was primarily built with a draft of 5.83 feet. This moderate draft strikes an ideal balance, keeping the vessel's center of gravity low while still allowing access to the shallow cruising grounds of the Bahamas and the US East Coast.
The vessel features a simple and robust masthead sloop rig. This configuration lowers the sail plan’s center of effort, reducing heeling forces and simplifying sail-handling systems for shorthanded crews. Tankage is exceptional and configured to support long-range motoring: the vessel carries a massive 570 gallons of diesel alongside 315 gallons of fresh water, making it one of the most self-sufficient cruising platforms in its size class.
Market Snapshot & Economics
Because the Portsmouth 48 was built as a niche, semi-custom cruiser, production numbers remained low. Consequently, these vessels are exceptionally scarce on the brokerage market. They command a premium among experienced cruisers who value Ted Hood's design pedigree and the versatility of a true motorsailer.
When evaluating one of these yachts, buyers must consider the unique economics of its heavy mechanical drivetrain. While a traditional sailboat engine is relatively inexpensive to service or replace, maintaining a 315-horsepower marine diesel demands a larger budget for parts, filtration, and fuel. Prospective owners should thoroughly inspect the engine installation, fuel delivery systems, and exhaust routing, as refitting a power plant of this scale in a sailing hull can be labor-intensive.
The Verdict
The Portsmouth 48 is an uncompromising passagemaker that occupies a rare sweet spot between offshore sailboat and long-range trawler. It is built to carry its crew safely through any weather, offering a level of comfort, mechanical redundancy, and raw motoring power that very few monohulls can match.
Pros
- Exceptional heavy-weather comfort and a safe, low capsize screening ratio.
- Massive fuel and water capacities designed for true off-grid self-sufficiency.
- High-horsepower engine delivers reliable, high-speed motoring when sailing is impractical.
- Excellent directional tracking due to its long keel design.
- High-end semi-custom construction with robust interior joinery and offshore-ready ergonomics.
Cons
- Conservative sail plan yields sluggish performance in light air.
- Long keel makes the boat less agile in tight marina quarters under power.
- Higher mechanical maintenance costs associated with a large-capacity diesel engine.
- Extremely limited availability on the used market makes finding one a challenge.
