Design and Construction
Norman Howard laid out a small monohull that SailWiki records as 4.95 meters overall with a 4.32-meter waterline and a 1.91-meter beam, proportions that give a length-to-beam ratio of 2.61. The hull and deck are solid fiberglass, and the boat carries a lead ballast in a stub keel with a centerboard that retracts to a minimum draft of 0.30 meter and extends to 0.76 meter. The early Seaborne-built examples — only sixteen of them — are noted to have a thicker laminate than the later Smallcraft boats, a construction distinction worth knowing among a fleet this small. With a displacement around 440 kg and a ballast ratio near 11 percent, the design sits at the very light end of the spectrum; its displacement-length ratio of 152 places it among what one reference calls "light racers," and the wetted surface of about nine square meters keeps the hull agile in the lower wind ranges.
Rig and Handling
The Senior is a fractional sloop carrying roughly 9.66 square meters of sail, enough to post a sail-area-to-displacement ratio of 17.01 and a stability index (S#) of 3.34. Period references list sheet dimensions that suit a boat handled by a short crew: a 12.4-meter mainsheet and 5.0-meter jib and genoa sheets, all sized at 8 mm, with a 10.9-meter spinnaker sheet for downwind work. The capsize screening value of 2.53 and a motion comfort ratio near 8.8 describe a tender, easily driven hull whose theoretical hull speed is about five knots. The shallow draft — as little as 0.98 foot under load — means the boat can be sailed onto a beach or a drying mooring, and an outboard of only one to two horsepower is typical for docking and close-quarters maneuvering.
Accommodations
Below, the boat is fitted with two berths, a minimal camp-cruiser arrangement consistent with a sixteen-foot coastal daysailer rather than a liveaboard. The immersion rate of about 307 pounds per inch shows how little weight shifts the waterline, so provisioning and crew placement matter more than on a larger yacht.
Refits and Ownership
Owners shopping the used fleet should note the builder variation: the sixteen Seaborne hulls predate the Smallcraft production run and carry heavier glass, while the remainder came from Blockley and at least one other yard. An active owners association at shipmate.org.uk supports the class with information sharing across its hundred-boat population.
The Verdict
The Shipmate Senior is a tiny, light, and easily launched coastal cruiser that rewards a sailor who wants beachable draft and simple systems over cabin volume. Its short waterline and modest sail plan keep it within the capabilities of a couple, while the centerboard and outboard setup make launching and recovery straightforward.
Pros
- Retractable centerboard gives 0.98-foot minimum draft for beaching and drying moorings
- Solid fiberglass hull and deck with known builder variants
- Low horsepower outboard suffices for docking
Cons
- Only two berths and minimal accommodation
- Very light displacement demands careful load management
- Small size limits offshore or extended cruising use
