Avance US1 Information, Review, Specs

Sailing Performance & Handling

The sailing characteristics of the US1 are defined by its Clark Mills-designed hull, which features a flat bottom and hard chines intended to promote early planing. While the standard Windmill is a sloop-rigged two-person boat, the US1 moves the mast forward to accommodate a single large mainsail (a cat rig). This configuration significantly reduces the workload for the helm, making it an ideal platform for solo recreational sailing or competitive single-handed racing.

With a beam of 4 feet, 9 inches and a total weight typically hovering around 230 pounds, the US1 is highly responsive to weight shifts and sail trim. The hull’s flat sections allow it to accelerate quickly on a reach, though like many hard-chine dinghies, it requires active hiking to keep flat in breezes above 10 knots. Technical commentary from the era suggests that while it lacks the upwind "pointing" ability of its sloop-rigged sibling due to the absence of a headsail to narrow the slot, its simplicity allows the sailor to focus entirely on hull trim and tactics. The boat uses a retractable centerboard, which provides the necessary lift upwind while allowing for easy beaching and shallow-water exploration.

Popular Mentions & Media

The US1 occupies a specific niche within the history of the Windmill Class, often cited as the preferred "single-handed" alternative for those who admired the Windmill’s speed but lacked a consistent crew. Its primary cultural footprint is found within the records of the National Sweet Sixteen Sailing Organization, which tracks the history of Advance Sailboat Corp. and its various models. While the US1 did not achieve the same international "one-design" status as the Windmill or the Optimist, it remains a respected example of Clark Mills' ability to adapt a racing hull for broader recreational appeal.

Known Issues & Buyer’s Checklist

Prospective owners of a vintage Advance US1 should focus their inspection on the structural integrity of the fiberglass and the specific stressors associated with a cat rig.

• Mast Step Integrity: Because the US1 is cat-rigged, the mast is stepped further forward than on a standard Windmill. This puts significant leverage on the forward deck and the mast step. Inspect for hairline fractures (crazing) in the gelcoat around the mast partner and ensure the step itself hasn't compressed the hull or floor.
• Centerboard Trunk Leaks: A common issue in Advance models of this era is the seal between the centerboard trunk and the hull. Over decades, the fiberglass bond can weaken, leading to persistent leaks when the boat is under load.
• Hull Rigidity: Given the age of these vessels (most were built between 1960 and 1980), "oil-canning" or soft spots in the fiberglass can occur, particularly on the flat bottom sections. Ensure the hull remains stiff and has not suffered from delamination due to water ingress in the core, if present.
• Hardware Backing: Early Advance boats often used wood or minimal metal backing for cleats and stays. Check that the shroud chainplates and the mainsheet block are securely fastened and haven't pulled through the fiberglass.

Community & Resources

While there is no longer a dedicated US1-specific manufacturer, the boat is often welcomed into the broader Windmill and Clark Mills design communities. The National Sweet Sixteen Sailing Organization serves as the primary historical repository for Advance Sailboat Corp. enthusiasts. Additionally, technical resources and rigging advice can frequently be found through the Windmill Class Association, as the hull dimensions and many underwater foils are identical between the two models.

The Verdict

The Advance US1 is a nimble, historic dinghy that offers a pure sailing experience for those who appreciate the design pedigree of Clark Mills.

Pros:

• Ease of Use: The cat rig simplifies rigging and tacking, making it an excellent solo boat.
• Planing Performance: The hard-chine Windmill hull is fast and exciting in a blow.
• Portability: Lightweight enough to be easily trailered by a small car or even roof-topped with sufficient hardware.

Cons:

• Aging Hulls: Most units require fiberglass restoration or gelcoat work due to their age.
• Limited Class Racing: Finding a dedicated US1 start is difficult; most must race in "Open" or Portsmouth Yardstick handicap fleets.
• Sensitivity: Like many lightweight dinghies, it can be "tippy" for beginners in gusty conditions.