This 16-foot-plus coastal dayboat combines a fractional-sloop rig with a stub/centreboard keel. Its proportions and construction point to a boat conceived for sheltered-water sailing rather than offshore passage-making.
Design and Construction
Norman Howard designed the Dayboat as a light-displacement coastal craft. It weighs roughly 675 pounds all-up, including a 90-pound lead ballast slug, for a ballast ratio of 13 percent. Its length-to-beam ratio is 2.61, giving it a narrow, easily driven hull just over 16 feet long, with a 14-foot waterline.
The boat was built with a stub/centreboard keel. The centreboard varies the draft from about one foot to 2.5 feet, allowing the boat to sail close to a beach and dry out where a fixed-keel design could not.
Both the hull and deck are solid fibreglass. Although Smallcraft of Blockley built most Dayboats, other yards also produced them. One Seaborne-built hull has a thicker lay-up than the later Smallcraft boats, so not every Dayboat has the same shell thickness.
Rig, Performance, and Handling
The fractional rig is simple and self-contained. The sail-control specifications are fully documented: jib and genoa sheets are 16.2 feet long and 5/16 inch in diameter, while the mainsheet is 40.6 feet of the same diameter. If the boat carries a spinnaker, the specified sheet length is 35.7 feet.
With around 104 square feet of sail and a displacement-length ratio of 106, the design falls into the “light racers” band. Its theoretical hull speed as a displacement boat is about five knots.
A motion comfort ratio of 6.1 is low, consistent with a lively, tender little dayboat rather than a smooth-riding cruiser. Its capsize screening value is 2.84, outside the threshold used to admit boats to ocean races. That confirms the design’s sheltered-water intent.
Auxiliary Power and Docking
An outboard is the standard auxiliary, intended for docking and manoeuvring rather than sustained propulsion. The boat typically needs only one to two horsepower, or an electric motor producing 13 to 16 pounds of thrust. This keeps the installation light and the transom uncluttered.
That modest power requirement reflects the Dayboat’s low displacement and the centreboard’s shallow-draft range.
Ownership and Maintenance
The wetted surface requiring antifouling is about 96 square feet, a small area that keeps bottom maintenance quick and inexpensive.
An immersion rate of roughly 307 pounds per inch means the boat sits lightly and responds visibly to changes in load. A few passengers or a full cooler will noticeably depress the waterline.
With a few hundred built before production ended in 1981, the Dayboat is established enough to appear on the used market, yet scarce enough that condition matters more than pedigree.
Verdict
The Shipmate Dayboat is a purpose-built, light-displacement dayboat: shallow-draft, beachable, easy to power, and inexpensive to maintain. It is also tender and, by its own stability figures, unsuited to the open ocean.
Pros
- Beachable stub/centreboard hull with a draft range of one foot to 2.5 feet
- Solid fibreglass construction and a small, inexpensive area to antifoul
- Minimal auxiliary-power requirement: 1–2 hp or an electric motor producing 13–16 pounds of thrust
Cons
- A capsize screening value of 2.84 excludes it from ocean racing
- The low motion comfort ratio of 6.1 indicates a lively, tender ride
- The thicker lay-up of one Seaborne-built hull complicates like-for-like comparisons
