Design and Construction
SailWiki records the Shipmate Senior as 4.95 meters overall, with a 4.32-meter waterline and a 1.91-meter beam. Those proportions give it a length-to-beam ratio of 2.61.
The hull and deck are solid fiberglass. Lead ballast is carried in the stub keel, while the centerboard reduces draft to 0.30 meter when raised and increases it to 0.76 meter when lowered.
Only 16 early examples were built by Seaborne. These are reported to have a thicker laminate than the later Smallcraft boats, a construction difference worth knowing in a fleet this small. Displacement is around 440 kg, with a ballast ratio near 11 percent. That puts the Senior at the very light end of the spectrum. Its displacement-length ratio of 152 falls within what one reference calls “light racers,” while a wetted surface of about nine square meters helps keep the hull agile in lighter winds.
Rig and Handling
The fractional-sloop rig carries roughly 9.66 square meters of sail, giving a sail-area-to-displacement ratio of 17.01 and a stability index (S#) of 3.34. Period references list running-rigging dimensions suited to a short-handed crew: a 12.4-meter mainsheet and 5.0-meter jib and genoa sheets, all 8 mm in diameter, plus a 10.9-meter spinnaker sheet for downwind work, all sized at 8 mm.
A capsize screening value of 2.53 and a motion comfort ratio near 8.8 describe a tender, easily driven hull. Theoretical hull speed is about five knots.
With as little as 0.98 foot of draft under load, the Senior can be sailed onto a beach or kept on a drying mooring. An outboard of only one to two horsepower is typical for docking and close-quarters maneuvering.
Accommodations and Load Carrying
Below, the Senior has two berths and a minimal camp-cruising arrangement, fitting for a 16-foot coastal daysailer rather than a liveaboard.
Its immersion rate of about 307 pounds per inch shows how little added weight is needed to change the waterline. Provisioning and crew placement therefore matter more than they would aboard a larger yacht.
Refits and Ownership
Used-boat buyers should note the variation between builders. The 16 Seaborne hulls predate the Smallcraft production run and carry heavier fiberglass laminates. The remainder came from Smallcraft of Blockley and at least one other yard.
An active owners association at shipmate.org.uk supports the class and allows owners to share information across the roughly 100-boat population.
The Verdict
The Shipmate Senior is a tiny, light coastal cruiser that’s easy to launch. It suits sailors who value beachable draft and simple systems more than cabin volume. Its short waterline and modest sail plan keep it within the capabilities of a couple, while the centerboard and outboard arrangement make launching and recovery straightforward.
Pros
- Retractable centerboard provides a 0.98-foot minimum draft for beaching and drying moorings
- Solid fiberglass hull and deck, with known differences between builder variants
- Low-horsepower outboard is sufficient for docking
Cons
- Only two berths and minimal accommodations
- Very light displacement requires careful load management
- Small size limits offshore or extended cruising use
