The Intro 22 is a significant, if niche, piece of maritime history, designed in 1975 by the prolific British naval architect David Thomas. Often overshadowed by its successor, the Hunter Sonata—which Thomas refined based on the Intro 22’s hull form—this 22-foot sloop was engineered as a competitive Mini Tonner that could double as a "pocket cruiser." Originally built in the United Kingdom by Seaglass, the model also saw limited production in Australia and was occasionally home-built in plywood. It represents an early era of the "performance cruiser" concept, where a wide beam and a light, stiff hull were used to maximize interior volume without sacrificing the sailing dynamics familiar to dinghy racers.
Intro 22 Information, Review, Specs

- Make
- Intro
- Model
- 22
- Builder
- Seaglass
- Designer
- David Thomas
- Number Built
- Production Year(s)
- 1975 - ??
Sailing Performance & Handling
The Intro 22 is characterized by a "lively" and responsive feel, often described by owners as a natural progression for those moving up from high-performance dinghies. With a displacement-to-length (D/L) ratio of approximately 206, the boat sits firmly in the "moderate racer" category, offering a blend of acceleration and enough heft to handle coastal chop. Its fractional rig—though many have since been converted to masthead configurations—provides a manageable sail plan that is easy to tune.
Under sail, the boat is notoriously stiff due to a high ballast ratio of roughly 43%, which allows it to carry its canvas longer than many of its 1970s peers. However, because of its exceptionally wide beam (over 9 feet on a 22-foot hull), the Intro 22 relies heavily on hull form stability. When over-canvassed, the boat has a tendency to develop significant weather helm and may "gripe" or round up into the wind if the mainsheet isn’t played actively in gusts. Despite its racing pedigree, the underwater profile features a distinct "kick" or upward sweep toward the transom, which effectively limits its ability to plane, keeping it a pure displacement hull even in high-wind reaching conditions.
Interior Comfort & Variations
For a vessel of its size, the Intro 22 offers remarkable internal volume, a direct result of its 9.16-foot beam. While the original racing versions prioritized a sparse, lightweight layout with simple bunks and a minimal galley, a "Cruising Version" was later popularized, particularly in the Australian market. This variant often features a full-length cabin trunk that provides increased headroom and a more civilized interior.
The cruising layout typically includes a V-berth forward, a compact galley, and a head—often located aft to port in Australian-built models like the well-documented Enki. The interior is often finished in a mix of molded GRP and teak trim, though some early timber-built examples may feature bespoke plywood cabinetry. Because the Intro 22 served as the developmental prototype for the Hunter Sonata, the interior feels like a slightly more "industrial" version of that highly successful production boat, with a focus on structural bulkheads rather than plush amenities.
Popular Mentions & Media
The Intro 22’s most notable claim to fame is its heritage as an offshore-capable small boat. In its early years, several examples were campaigned in the grueling Mini Transat 6.50, a solo race across the Atlantic that solidified the boat's reputation for toughness. While it lacks a modern media presence, it remains a favorite subject in specialized design forums such as Boat Design Net, where enthusiasts discuss its lineage alongside other David Thomas classics like the Sigma 33.
Known Issues & Buyer’s Checklist
Prospective buyers should approach the Intro 22 with an eye for structural integrity, particularly given the age and the racing history of many hulls.
- Chainplate Ingress: A frequent point of failure is the deck seal around the shroud chainplates. Water often leaks into the bulkheads that support these plates, leading to rot or structural softening.
- Rudder Assembly: The transom-hung rudder is subject to high loads due to the boat’s beam and potential weather helm. Owners have reported rudder failures, and the design of the pintles and gudgeons should be inspected for stress fractures or excessive play.
- Rig Modifications: Many Intro 22s were modified from their original fractional rigs to masthead rigs or had their masts shortened for inland sailing. These changes can dramatically alter the center of effort and lead to heavy steering.
- Keel Attachment: The iron fin keel is through-bolted to a relatively shallow sump. Inspect the "Catalina smile" (cracking at the leading edge of the keel-to-hull joint) and verify the condition of the keel bolts, as these are known to rust if the bilge has been habitually wet.
Community & Resources
While no dedicated "Intro 22 Class Association" remains active, technical support is frequently found through the Hunter Sonata National Class Association, given the near-identical hull dimensions. Technical drawings and original brochures are rare, but community archives on forums like the Minitonner ProBoards often house scans of the original David Thomas sail plans.
The Verdict
The Intro 22 is an uncompromising "little-big boat" that offers the interior space of a 25-footer with the agility of a racing dinghy. It is ideally suited for a budget-conscious sailor who enjoys active, technical sailing and wants a boat capable of occasional coastal hopping.
Pros:
- Exceptional interior volume for its length.
- High ballast ratio provides a stable, "big boat" feel.
- Competitively priced compared to its more famous sibling, the Hunter Sonata.
- Historically proven offshore durability.
Cons:
- Requires active sail trimming to manage weather helm.
- Displacement hull design prevents true planing.
- Limited market availability and lack of original parts/plans.
- Vulnerable to deck and bulkhead rot around chainplate attachments.
Measurements
Construction & Hull
- Construction Material
- Fiberglass/Wood Composite
- Hull Type
- Monohull Sailboat
- Keel Type
- Fin
- Rudder
- 1x Transom-Hung
- Ballast
- 1200 lbs (Iron)
- Displacement
- 2800 lbs
- Water Capacity
- -
- Fuel Capacity
- -
Dimensions
- Length Overall (LOA)
- 21.75 ft
- Waterline Length (LWL)
- 18.24 ft
- Beam
- 9.16 ft
- Draft
- 4.58 ft
- Max Headroom
- -
- Air Draft
- -
Rig & Sails
- Rig Type
- Fractional Sloop
- P (Main Luff)
- 27 ft
- E (Main Foot)
- 7.8 ft
- I (Foretriangle Height)
- 27 ft
- J (Foretriangle Base)
- 8.5 ft
- Forestay Length (est)
- 28.31 ft
- Sail Area
- 279 sqft
Calculations
- Sail Area / Displacement (SA/D) Ratio
- 22.47
- Ballast / Displacement Ratio
- 42.86
- Displacement / Length Ratio (D/L) Ratio
- 205.98
- Comfort Ratio
- 11.74
- Capsize Screening Formula
- 2.6
- Hull Speed
- 5.72 kn