The search results provide a lot of valuable information.
Key Findings:
- Designer: Alan Buchanan (naval architect) designed the Diamond 27 and its successor, the Halcyon 27.
- Builder: Originally built by Stebbings & Sons and Thames Marine. Thames Marine built it between 1963 and 1966.
- Successor: In 1966, Offshore Yachts acquired the molds and renamed the boat the Halcyon 27, continuing production until around 1975, with about 200 built under this name.
- Variations: The notes mention the DIAMOND MKII and that an earlier version had a fractional rig. The Halcyon 27 is a masthead sloop. One forum post mentions "Not so much of a problem with masthead rig but a real problem with fractional rig" in the context of mast stepping, confirming the existence of both rig types. Another forum refers to an "early example of a Halcyon 27". The states the Diamond 27 is a masthead sloop. It seems the fractional rig was on an earlier Diamond version, preceding the MKII.
- Design Philosophy (Buchanan): Alan Buchanan is a renowned British maritime designer. His designs are often described as classic small offshore cruisers, tough, seaworthy, and capable. The Halcyon 27 is considered a folkboat derivative with its long keel and transom-hung rudder. Buchanan was known for designing sturdy, well-regarded boats.
- Sailing Characteristics:
- Long keel: Provides better directional stability but less maneuverability than a fin keel, especially when going astern.
- Seaworthy: Described as a "tough, seaworthy little boat". One owner sailed one around the world and survived two major storms, highlighting its seaworthiness.
- Performance: "Sailed well". "Very powerful performance". Some consider it old-fashioned and cramped by modern standards.
- Stiffness/Stability: "immensely seaworthy". When caught in a nasty squall, "she simply lay over until" the stresses on the rigging were low, making capsize unlikely.
- Accommodations and Layout:
- "Useful accommodation".
- "Cramped" by modern standards, a "small boat for its length".
- Sleeps four: a double forward cabin (V-berth) and two berths in the saloon.
- Includes a navigation station and galley.
- One forum post mentions a "50 mm flange moulded in the base of the cockpit", suggesting drainage or engine access.
- General layout: forecabin and saloon.
- Owner's Perspectives:
- Strengths: Very well regarded in its day. Strongly built. Sails well, powerful performance. Tough, seaworthy, capable. Good value.
- Weaknesses/Common Issues: Considered old-fashioned and cramped by modern standards. "Tricky when going astern" due to the long keel. One owner found "loose, corroded iron" in the transom locker. Maintenance/repairs and upgrades are common for these older boats. Original deck fittings might be a potential issue, though not explicitly stated as a common problem, it's a general point for older boats.
Now I have enough information to structure the article.
Refined Plan:
- Introduction: Mention Alan Buchanan, Thames Marine, Offshore Yachts (Halcyon 27 link), purpose (cruiser), reputation (sturdy, seaworthy).
- History and Design: Production years, Buchanan's design philosophy (classic small offshore cruiser, folkboat derivative), Thames Marine's fiberglass ethos, the transition to Halcyon 27, and the MkII/rig variations.
- Sailing Performance and Handling: Interpret SA/D (14.2 - light air performance), B/D (0.50 - stiffness/stability), D/L (322.65 - heavy cruiser). Describe handling (long keel, directional stability, less maneuverable astern), seaworthiness.
- Accommodations and Layout: Describe the four-berth layout (V-berth, saloon berths), galley, nav station. Comment on it being "useful" but "cramped" by modern standards. Mention general construction (fiberglass).
- Owner's Perspectives: Synthesize praise for strong build, seaworthiness, performance. Mention common critiques like "cramped" and "tricky astern," and potential for general maintenance on older boats.
I will ensure to cite all information from the search results. I will also make sure the tone is that of a knowledgeable marine journalist.