At a time when competitors relied on heavy, flexible solid-fiberglass layups to save on manufacturing costs, S2 opted for a technologically advanced approach. The company integrated the 5.5 into their performance-oriented Grand Slam series, which employed high-end balsa-cored lamination techniques to maximize stiffness and shed unnecessary weight. This resulted in an athletic, ultra-light displacement boat that offered a refined, "big boat" feel in terms of hardware and deck execution, yet delivered the kinetic thrills of an open-class racing dinghy.
Design Brief & Intent
In the early 1980s, the small-boat market was saturated with heavy pocket cruisers and entry-level daysailers that favored cost-efficiency over sailing dynamics. S2 Yachts launched the Grand Slam 5.5 to capture the sailing purist who demanded responsiveness, trailerable convenience, and uncompromising build quality. Don Wennersten’s design brief focused on creating a stiff, easily managed racer-daysailer that could be ramp-launched and sailed in thin water, yet still carry the premium finish and hardware of S2's larger cruising yachts.
This quality is immediately noticeable in the boat's clean deck layout, heavily backed load-bearing hardware, and precise fiberglass moldings. Because the 5.5 was designed with a performance-first mindset, the accommodations are strictly minimalist. The boat lacks a true cruising cabin; instead, a low-profile forward cuddy deck serves exclusively as dry stowage for sails, gear, and an outboard motor. There are no berths or standing headroom. The heart of the design is its expansive, ergonomically optimized open cockpit, which provides ample space for a crew of two to four to hike out comfortably, while keeping all control lines within easy reach of a solo skipper.
Rigging & Sailing Performance
Under sail, the S2 5.5 is highly communicative, responsive, and rewarding. Weighing in at a featherlight displacement of 600 pounds, the hull behaves like a true racing dinghy. It reacts instantaneously to helm inputs and crew weight placement, demanding an active sailing style. The rig is configured as a fractional sloop with a tall, high-aspect mainsail and a smaller headsail. This sailplan, boastng an extraordinarily high sail area to displacement ratio of 39.58, makes the boat a formidable light-air weapon. It will easily ghost along and build apparent wind when heavier, moderate-displacement daysailers are left becalmed.
As the breeze builds, the boat’s handling becomes highly exhilarating. With a displacement to length ratio of 62.42, the S2 5.5 is classified as an ultra-light displacement vessel, meaning it is fully capable of jumping onto a plane when sailing off the wind. However, this light weight comes with a trade-off in stability. The capsize screening ratio of 3.64 is high, reflecting the fact that the boat has no heavy ballast keel. Instead, it relies heavily on the dynamic placement of crew weight and quick mainsheet trimming to stay upright in a blow. This flighty nature is reinforced by a comfort ratio of 3.66, which indicates that the hull will pitch and roll quickly with every wave.
The underwater profile features a pivoting, trunk-mounted retractable centerboard and a transom-hung, kick-up rudder 1. With the board fully extended to its four-foot draft, the 5.5 tracks beautifully upwind with minimal leeway. When returning to port, the board can be pulled completely flush into the trunk, reducing the draft to just six inches, which allows the skipper to beach the boat or glide over shallow sandbars with ease.
Known Issues & Triage
Although S2 built their hulls and decks to an admirable standard, the core materials that give the Grand Slam 5.5 its high strength-to-weight ratio are also its greatest structural vulnerability today. Both the deck and the hull utilize balsa-coring. Over decades of use, any unsealed fastener, poorly bedded cleat, or hairline fracture in the gelcoat can allow water to penetrate the laminate. Once moisture enters, it migrates through the balsa wood, leading to rot, delamination, and spongy, structurally compromised panels. Buyers must inspect these boats thoroughly with a moisture meter and a sounding hammer, paying close attention to high-load areas around the chainplates, mast step, and deck cleats.
The centerboard assembly is another common area requiring maintenance triage. The pivoting centerboard relies on an internal pin and a lifting pennant 1. Over time, the pivot pin can wear, resulting in a knocking sound when sailing or causing minor leaks around the trunk-to-hull seal. The lifting pennant and its pulleys are prone to chafe and must be checked for wear; replacing a snapped centerboard line on a trailer is a notoriously difficult task. Additionally, the high rudder loads experienced when sailing at high speeds can cause the transom-hung gudgeons to wallow out or stress the surrounding laminate, necessitating fiberglass reinforcement or custom bushings.
Market Snapshot & Economics
Because the S2 5.5 was only produced from 1982 to 1983, with approximately 70 hulls completed, it is a rare find on the brokerage market today. It is highly regarded by a niche community of classic S2 owners and dinghy enthusiasts. The boat holds its value well on the secondary market relative to its size, commanding a small premium over generic, similarly sized daysailers due to its superior stiffness, fractional rig, and performance pedigree.
The economics of a refit are highly favorable, provided the balsa core is dry. The lack of an inboard engine, complex marine plumbing, or an onboard electrical grid means that restoration costs are minimal. Propulsion is generally handled by a small two-horsepower to four-horsepower outboard motor mounted on a simple transom bracket. This mechanical simplicity allows owner-builders to easily restore the boat to like-new condition in a driveway.
The Verdict
The S2 5.5 Grand Slam is a classic, high-performance micro-racer that delivers an athletic, engaging sailing experience. It is not a casual, sit-in pocket cruiser, but rather a sophisticated dinghy designed for those who appreciate responsive handling, high-quality composite construction, and the ability to explore shallow waters. For sailors looking for a low-maintenance, easily trailerable boat with an impressive pedigree, it remains a compelling choice.
- Pros
- Outstanding light-air performance and acceleration thanks to a powerful sail plan.
- Highly trailerable and easy to ramp-launch with a draft of only six inches when the board is raised.
- Superior structural stiffness and build quality compared to other daysailers of its era.
- Minimal maintenance overhead due to simple rigging and a lack of complex onboard systems.
- Responsive, communicative helm that rewards active sail trim and precise steering.
- Cons
- High vulnerability to balsa-core rot in both the deck and hull if moisture is allowed to penetrate the laminate.
- Complete lack of cruising accommodations, offering only a small cuddy cabin for gear storage.
- Flighty, dinghy-like motion that can be wet and exhausting for inexperienced crews in heavy weather.
- Relying on active crew weight and mainsheet handling to maintain stability due to the lack of a ballasted keel.
- Extreme rarity makes locating original replacement parts or finding sisterships difficult.
