18′ 8″ Mackinaw Boat

18'8'' Mackinaw Boat

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This boat is an historically accurate 18′ version of the well-known, reputed Mackinaw boat, a sailing and rowing shallop type that was popular on Lakes Michigan and Superior in the late 1800s. The originals, which ran 26′ or more, were known for their speed and seakeeping abili­ties, and this smaller version should exhibit many of the same endearing qualities.

Construction of Zimmer’s Mackinaw is straightforward plank-on-frame. Other building methods seem appropriate: lapstrake (traditional or glued), strip-plank composite, or cold-molded.

Designed by Nelson Zimmer, the Mackinaw Boat has a LOA of 18′ 8″, a 6′ beam, and draws 1′ 6″ with her center­board raised. Her shoal draft will enable her to poke about in shallow waters and ground out at her mooring at low tide without trouble.

The traditional plank-on-frame construction will satisfy experienced hands and teach newcomers.

Her spars and gear are simple and inexpensive. An unusual detail is the main and mizzen halyards’ arrange­ment, combining peak and throat into one line for each sail. Oars serve as auxiliary power. Being long-keeled, she won’t tack very quickly, but with the right breeze, she’ll provide a good turn of speed. This roomy, shoal-draft boat will give a good account of herself in a broad range of wind and sea conditions, and with a variety of loads. She could be trail­ered, or simply hauled up on the beach for winter.

The 27′ late-19th century Mackinaw (drawn by Howard Chapelle from a half model) influenced designer Nelson Zimmer.

The plans for the Mackinaw Boat show good detail, and an experienced amateur or a professional would be able to build her. Although she is best suited for carvel planking, some similar boats have been built lapstrake. We recom­mend white cedar and oak, but red cedar, yellow cedar, or western fir would be alternative choices. The denser woods such as hard mahogany should be avoided.

Set the station molds perpendicular to the keel, and bend in the frames with the same orientation.

Further information is available in WB No. 45, WB No. 23 in the “Tidings” and “Designs” sections, and in Howard Chapelle’s American Small Sailing Craft. (This last refer­ence is for the original.) WB Plan No. 14. $60.00.

Mackinaw Boat Plan Highlights

DESCRIPTION
Hull type: Round-bottomed double-ender with centerboard
Rig: Gaff ketch
Construction: Carvel planked over steamed frames Featured in Design Section: WB No. 23

PERFORMANCE
* Suitable for: Somewhat protected waters
* Intended capacity: 3-5
* See page 112 for further information.
Trailerable: Yes
Propulsion: Sail, oars, outboard Speed (knots): 3-5

BUILDING DATA
Skill needed: Intermediate to advanced
Lofting required: Yes
*Alternative construction: Lapstrake, strip, or cold-molded

PLANS DATA
No. of sheets: 3
Level of detail: Average
Cost per set: $60.00
WB Plan No. 14

Completed 18’8” Mackinaw Boat Images

Photo by Matthew P. Murphy

This 18’ Mackinaw will sail in a range of conditions, though the first reef must be taken early. The reef nettles seen flying here are on the mainsail; they’re the last of four options, before dousing everything and proceeding under bare poles.

Being long-keeled, she won’t tack very quickly, but with the right breeze, she’ll provide a good turn of speed.

The plank-on-frame construction features Northern White Cedar planking and White Oak for the keel, frames, and centerboard trunk.