The Halcyon 23 is a British trailerable sailing boat that was designed by Alan Buchanan as a cruiser and first built in 1967.

[1][3][6] The Halcyon 23 is a recreational keelboat, built predominantly of glassfibre, with wood trim.

It has a masthead sloop rig, a spooned raked stem, an angled transom, a transom-hung rudder controlled by a tiller and a fixed fin keel with a weighted bulb or optional triple keels with steel plate side fins.

[1][3] The boat was factory-fitted with a number of powerplants for docking and manoeuvring, including the British Stuart-Turner petrol engine.

The ballast weight is shown here as 1,100 pounds, but 900 of these are mostly in a bulb at the bottom of a fin keel, so ultimately her ability to stand up in a blow would likely be significantly greater than the boat's comp[etitor]s, all of which are centerboarders with inside ballast.