Design Brief & Intent
The Edwardsson 707 was designed as an antidote to the conservative, heavily compromised cruising boats of its time, such as the Maxi 77 or Albin Vega. While those models focused on maximize headroom, high freeboard, and heavy interior joinery, the Edwardsson brothers prioritized an easily driven, lightweight hull with a fractional rig. It was a boat intended for active club racing and minimal, weekend-style coastal cruising.
Because the boat was primarily marketed as a "byggsats" (self-build kit) to keep costs low, the interior execution varies significantly across the fleet. Early hulls finished entirely by amateur builders can feature highly idiosyncratic joinery, varying grades of plywood, and sparse layouts. To bring consistency to production, hulls from number 70 onward were equipped with an inner fiberglass structural lining ("basinrede"). This layout standardized a functional four-berth arrangement. Even with the interior module, accommodations remain distinctly Spartan with limited headroom and a focus on weight savings, making the cabin more of an overnight shelter than a comfortable home afloat.
Sailing Performance & Handling
The sailing performance of the Edwardsson 707 is defined by its unusual structural ratios. At a featherweight displacement of just 1,984 pounds, the boat carries an extraordinarily high ballast ratio of nearly 60 percent (59.98%). This massive concentration of weight—1,190 pounds of iron cast into a low-drag, L-shaped bulb fin keel—gives the 707 an immense amount of righting moment for a boat of its size.
The sail area-to-displacement ratio of 23.1 signals an incredibly powerful and responsive sail plan. The fractional rig utilizes a highly tunable mast with swept-back spreaders, allowing crews to bend the spar and de-power the mainsail as the wind builds. Helming the 707 feels more akin to steering a modern sportboat than a classic 1970s cruiser; it accelerates out of tacks instantly and responds beautifully to active mainsheet trimming. However, with a low comfort ratio of 11.92 and a displacement-to-length ratio of 128.52, the ride is decidedly lively. The boat moves quickly over and through waves, and its capsize screening value of 2.14 reflects a relatively narrow beam (6.73 feet) and lightweight hull that is built for speed and agility rather than offshore security. Downwind, the boat relies on a generous 34.2-square-meter spinnaker to maintain its blistering pace, where it can easily out-sail much larger traditional yachts.
Known Issues & Triage
Given the amateur-completed nature of many Edwardsson 707s, structural inspection is critical, as build quality is highly inconsistent.
- Keel Joint Movement: A known issue on some early hulls is movement in the keel-to-hull joint. The cast-iron L-keel was occasionally bedded in a flexible single-component sealant like Sikaflex rather than a rigid structural matrix. Over time, this allows the keel to flex slightly against the hull. The standard triage involves dropping the keel, cleaning the mating surfaces, and re-bedding it with structural epoxy thickened with an additive like talk or microfibers.
- Chainplate and Deck Flexing: The high rig tension required to keep the fractional headstay straight can place immense stress on the deck. Many owners have noted that the deck flexes when the backstay is hard on. Installing aftermarket stainless steel chainplate support struts (röstjärnsstöttor) down to the structural floor grid is a highly recommended modification to transfer these loads directly to the hull.
- Deck Core Wetness: The deck is constructed of a fiberglass sandwich with a balsa or foam core. Standard checks for soft spots or elevated moisture readings around the chainplates, mast step, and deck organizers are mandatory, as sealing practices by original DIY builders were not always up to professional yard standards.
Modernization & Upgrades
Modern owners continue to refine the Edwardsson 707 to keep it competitive and easy to handle shorthand.
- Rudder Profiles: The original transom-hung rudder can feel heavy and prone to stalling when the boat is pressed hard. A common high-performance modification is replacing the stock rudder blade with a modern, high-aspect foil—often retrofitting profiles from sportboats like the Melges 24 or CB66—to reduce drag and improve steering authority.
- Rigging and Deck Layout: Upgrading to modern low-friction deck hardware is a popular choice. Owners frequently install modern cam cleats, Harken self-tailing winches, and Dyneema backstays and halyards. Some racers have also fitted lightweight carbon bowsprits to run modern asymmetrical spinnakers, making downwind handling far easier than using a traditional spinnaker pole setup.
- Propulsion: Because the boat has no inboard engine, it relies on an outboard motor mounted on a transom bracket. The light weight of the hull makes it an ideal candidate for modern electric outboard conversions. A lightweight, 1kW to 3kW electric outboard (equivalent to a 3 to 4 horsepower gas motor) saves significant weight on the stern, eliminates fuel storage issues in the cockpit, and aligns with the boat’s minimalist ethos.
The Verdict
The Edwardsson 707 is a brilliant example of uncompromising Swedish engineering. It delivers an exhilarating, high-performance sailing experience that punches well above its weight class, all while keeping operational and maintenance costs exceptionally low. It is not a boat for those seeking standing headroom, comfortable cruising cabins, or heavy-displacement sea-kindliness. Instead, it remains an affordable, incredibly stiff, and rewarding pocket rocket for sailors who prioritize pure performance on the water.
Pros:
- Exceptional stiffness and stability due to an almost 60% ballast ratio.
- Highly responsive and fast performance, out-sailing many larger, heavier pocket cruisers.
- Easily trailerable and simple to launch, maintain, and store.
- Highly suitable for modern electric outboard conversions due to its light weight.
- Affordable entry point into high-performance, responsive sailing.
Cons:
- Highly variable build quality due to many hulls being finished by amateur kit-builders.
- Extremely limited interior comfort, low headroom, and Spartan accommodations.
- Lively, motion-heavy ride in a seaway due to a low comfort ratio.
- High rig tension requirements can cause deck flex if structural reinforcements are not installed.
