Design Brief & Intent
Kim Swarbrick designed the Spacesailer 20 with a demanding regional testing ground in mind: Western Australia’s Swan River and the adjacent Indian Ocean. This environment is defined by the "Fremantle Doctor," a fierce afternoon sea breeze that regularly pipes up to 20 or 25 knots. While European and North American builders of the same era were designing lightweight, lightly ballasted trailer sailers optimized for calm inland lakes, Swarbrick focused on structural robustness and heavy-weather survival. The hull was laid up with thick, hand-laid fiberglass to handle choppy waters and accidental groundings. It was built for entry-level sailors, young families, and active club racers who wanted a reliable, low-maintenance boat that could punch above its weight class.
Inside, the boat features a highly practical, molded fiberglass interior liner that adds structural rigidity while keeping maintenance simple. The layout accommodates up to four berths, comprising a forward V-berth and two quarter berths extending beneath the cockpit. While the cabin is cozy and admittedly tight for multiple adults on extended trips, it provides a dry, secure shelter for weekend pocket-cruising. Minimalist interior modules provide dedicated space for a small slide-out galley, a sink, an icebox, and a chemical head tucked beneath the forward berth. The interior joinery is simple and functional, prioritizing low weight and ease of cleaning over the heavy, teak-intensive fit-outs of larger cruising yachts.
Variations & Configurations
The Spacesailer 20 was produced in two primary configurations that altered its draft, stability, and ease of transport. The fixed-fin keel version, drawing 3.5 feet (1.07 meters), features a substantial cast-iron or lead bulb. This configuration was favored by sailing clubs and owners keeping their boats on moorings, as it eliminated the moving parts and maintenance of a centerboard trunk while maximizing righting moment.
For owners prioritizing mobility, a swing-keel (or retractable-keel) model was produced. This variable-draft version allowed the boat to be ramp-launched from a standard tandem-axle trailer, making it easy to tow behind a family vehicle and opening up shallow estuaries, rivers, and beach anchorages. Later in the production run, a modified drop-keel Mk II variant was introduced, which refined the lifting keel mechanism to minimize trunk play and vibration. Swarbrick also offered variations in rig sizes, including a standard and a short masthead sloop configuration, allowing original buyers to optimize the sail area based on local wind conditions.
Sailing Performance & Handling
The sailing characteristics of the Spacesailer 20 are defined by its reassuring stiffness and balanced handling. The boat's displacement of 1,900 pounds includes 700 pounds of ballast, yielding a ballast-to-displacement ratio of 36.84 percent. In real-world terms, this high ratio ensures that the boat remains upright and under control when the wind gusts, allowing short-handed crews to carry full canvas much longer than they could on flimsier trailer sailers of the same era.
Its displacement-to-length ratio of 145.44 places the boat firmly in the light-displacement category. The hull is easily driven and responds eagerly to light breezes, accelerating quickly out of tacks and handling cleanly on all points of sail.
A capsize screening ratio of 2.53 indicates that the Spacesailer 20 is mathematically categorized as a day-boat or coastal cruiser. While it has excellent initial stability and has successfully completed ambitious coastal passages, its hull geometry is not intended to self-right in the face of extreme, breaking offshore seas. This is matched by a comfort ratio of 10.18, indicating a lively, active motion in a seaway. The boat will rise and fall rapidly over chop rather than slicing heavily through it. This active motion provides immediate helm feedback, making the boat an exceptional and responsive teaching platform, though it can be physically tiring on long, choppy passages.
Known Issues & Triage
Given the age of the fleet, prospective buyers must evaluate several key areas for structural wear and water damage. The most critical structural concern centers on the chainplate attachments. The shroud chainplates are bolted through the deck and directly into the plywood bulkheads. Over decades, the original deck seals degrade, allowing rainwater or saltwater to migrate into the wood. This causes localized rot and "mushiness" in the bulkhead, which can lead to chainplate lifting under load and subsequent rig failure. Inspecting the bulkhead wood for staining, soft spots, or fastener movement is a necessary first step, and rebuilding or reinforcing these bulkheads with marine grade plywood is a common DIY project.
Deck delamination is another common vintage-fiberglass issue. The deck contains a coring material that can suffer from water penetration around the mast step, stanchion bases, and deck cleats. Walking the deck to feel for soft spots and tapping the surface with a plastic-tipped sounding hammer to listen for hollow tones will identify areas of moisture intrusion. Localized epoxy injection or recoring with marine plywood or closed-cell foam is the standard repair method.
On swing-keel models, the keel trunk, pivot bolt, and lifting assembly require close inspection. The cast-iron swing keel is subject to crevice corrosion, which can cause the metal to swell and jam inside the fiberglass trunk. The stainless steel pivot bolt must be periodically inspected and replaced to prevent catastrophic keel loss, and the winch cable should be treated as a regular maintenance item. Finally, the original acrylic cabin windows often leak due to dried-out bedding compound; pulling, cleaning, and re-bonding the windows is required to keep the interior cabin dry.
Modernization & Upgrades
The simple systems of the Spacesailer 20 make it a highly rewarding platform for modernization and custom refits. Upgrading the electrical system to lithium iron phosphate (LiFePO4) battery technology has become a popular modification. Replacing the heavy, original lead-acid batteries with a single 50Ah or 100Ah lithium battery sheds valuable weight while providing more than enough usable capacity to power modern depth sounders, VHF radios, LED cabin lighting, and mobile devices. To keep this bank topped up indefinitely, many owners mount a thin, flexible 50W to 100W solar panel on the companionway hatch garage or a custom stern rail mount.
Repowering is another common area of owner upgrade. While many boats still use older two-stroke outboards, many owners have retrofitted modern, long-shaft 4-horsepower to 6-horsepower four-stroke outboards, which offer quiet, fuel-efficient operation and integrated battery charging. Because of the boat’s modest 1,900-pound displacement, it is also an ideal candidate for electric outboard conversions. Quiet, lightweight electric outboards eliminate the need for carrying flammable onboard gasoline, require virtually no annual maintenance, and easily drive the hull to its nominal hull speed of 5.7 knots.
The Verdict
The Spacesailer 20 is a rugged, beautifully designed pocket cruiser that offers an exceptional balance of heavy-weather stability, simple systems, and sailing responsiveness. Purpose-built to handle challenging coastal conditions, it provides a level of peace of mind rarely found in modern, ultra-lightweight trailer sailers. While its cabin interior is snug and best suited for minimalist weekend camping rather than extended cruising, its massive cockpit and forgiving handling make it an outstanding entry-level boat, an affordable club racer, or a low-stress day-boat.
- Exceptional heavy-weather stiffness and stability for a 20-foot boat, standing up well to high winds
- Robust hand-laid fiberglass hull construction provides excellent structural durability
- Highly responsive and rewarding helm feedback, making it an excellent teaching platform
- Available in both fixed-fin and trailerable swing-keel configurations to suit different launching and sailing needs
- Low-maintenance deck and molded interior fiberglass liner keep ongoing upkeep simple
- Snug and spartan interior cabin with limited headroom and minimal amenities
- Lively, quick motion in a chop that can be tiring on long, single-day passages
- Older models require careful inspection for bulkhead rot around the chainplates and deck delamination
- Swing-keel models require ongoing maintenance of the pivot bolt, cable, and trunk
