Design and Construction
Roberts conceived the RC-27 as a thoroughly modern lightweight cruiser-racer, and the numbers tell the story. The bare hull and structure weigh only 750 pounds excluding sails and spinnaker rigging, a figure that explains both the boat's responsiveness and her classification as an ultra-light design. The hull is fiberglass, built by Aquarius Sail Inc. in the United States, and the platform carries a daggerboard keel rather than fixed appendages. That board, combined with rudders only, gives a draft of 3 feet; with the board lowered the draft reaches 4 feet 6 inches. The shallow rudders-only figure lets the boat settle into remarkably thin water, and reviewers noted she can tuck into shallow marinas because the draft runs roughly 0.91 to 1.01 meters depending on load.
Rig and Handling
The RC-27 is rigged as a fractional sloop with a spar length of 44 feet. That tall, fractionally stayed rig drives a very light hull, and the displacement-length ratio of 17 confirms the boat belongs in the ultra-light racer category rather than the cruising mainstream. The daggerboard gives the sailor a draft choice: lifted for gunkholing and lowered for upwind grip. The 16-foot beam produces a broad, stable platform, and the 1.72 length-to-beam ratio is what yields the exceptional interior volume reviewers highlighted.
Accommodations
The beam defines the RC-27's interior character. At 16 feet across on a 27-foot 6-inch hull, the length-to-beam ratio of 1.72 makes the boat roomier than 99 percent of similar sail catamarans, a proportion that translates directly into livable space below and on the bridgedeck for a vessel of this length. The lightweight construction keeps the structure minimal, but the footprint is what sets the design apart from narrower monohulls and catamarans of the same overall length.
The Verdict
The Aquarius RC-27 is a specialized lightweight catamaran that trades ballast and mass for space and speed potential. Roberts' mid-eighties design, built by Aquarius Sail Inc., uses a 16-foot beam on a 27-foot 6-inch hull to deliver interior volume almost no comparable catamaran matches, while the 750-pound bare weight and daggerboard make her a shallow-draft racer-cruiser. She is not a heavy-weather voyager by constitution, but as an ultra-light day sailor and coastal catamaran she occupies a distinctive niche.
Pros
- Beam of 16 feet gives more space than 99 percent of similar sail catamarans
- Bare weight of 750 pounds and daggerboard make for a shallow-draft platform
- Fractional sloop rig with 44-foot spar on a 27-foot waterline suits light-air performance
Cons
- Ultra-light displacement (DL-ratio 17) limits her to the racer end of the spectrum rather than loaded cruising
- No ballast or tankage figures are published for the design
