A classic mahogany runabout
CATEGORY: Classic Mahogany Runabouts
CONSTRUCTION: Cold-Molded/Epoxy Planking
The BISCAYNE 18 & 22 classic mahogany runabout designs capture the look and feel of production runabouts built in the several years either side of 1940, and incorporate similar hull shapes accordingly. That means reverse-curved flaring topsides at the bow blending gracefully aft to a generous tumblehome at the transom. Such attractive contours are impossible to build using sheet plywood alone, yet easily reproduced using our carefully detailed building methods.
Also, notice the gentle reversed sheer profile lines of these designs. They incorporate enough "heft" within the specially-designed structure so you can create that soft "rolled edge" gunnel. That's a prime feature giving these boats the elegance missing in more "ordinary" runabouts of similar size. Couple this with the authentic "plumb" stem and careful cockpit/deck detailing and you have a boat with true classic authenticity.
But beyond the authentic styling of our Biscayne 18 & 22 is both a superior boat and one that will cost a fraction of a new replica or restored original. It's all due to our modern wood-epoxy "cold-molded" planking method that prevents leaking joints and flexing hulls that can detract from performance and longevity. If boats of the past had had such technology, they would have been built this way.
Using double diagonal ply/veneer planking, there are no rabbets to cut, no steam bending, no caulked seams, and no lofting. Bottom thickness totals ½" (four layers) with 3/8" topsides (three layers with the final appearance layer applied lengthwise). Planking is reinforced inside by a series of longitudinal stiffeners wrapped around a series of husky sawn wood frames and other backbone members. The result? A stiff, strong, durable yet lightweight hull that's free from rot and easy to maintain.
Power comes from a direct drive motor located amidships. We prefer a contemporary power plant over traditional motors that are sometimes still available because they are lighter in weight, more compact, more reliable, and offer higher output for their size. Usually gasoline motors are used, but diesel is an option as long as weight won't exceed that of the largest gasoline type that might be found within our listed displacement ratings.
However, we advise against overpowering these boats; practical speeds should be limited to the 30's and 40's. And if using longer in-line motors, and/or those that may be on the heavy side, we would recommend considering building the longer option hull included with both designs. This is done by respacing frames proportionately so appearance features are retained. Shortening these boats, however, is not recommended.
Plans with instructions aimed at the amateur craftsman include all the details along with material listing, fastening schedule, and resource list to help you track down what you need. Also provided are FULL SIZE PATTERNS for the sawn frame and backbone members so lofting is not required.
Can you build your own Mahogany Runabout? Read our article to find out.
- Length overall:
- 21'10"
- Length option:
- 22'11"
- Beam:
- 6'8"
- Draft w/prop:
- 21"
- Freeboard fwd:
- 2'5"
- Freeboard aft:
- 1'6"
- Passengers:
- 8
- Motor type:
- V6; V8
- Motor cu in:
- 220-330
- Fuel capacity:
- 40 gals.
- Hull wt approx.:
- 1000 lbs.
- Cockpit size - L x W - Forward:
- 2'6" x 5'5"
- Cockpit size - L x W - Aft:
- 2'5" x 4'3"
- Cockpit size - L x W - Mid:
- 2'5" x 5'6"