CLC’s Expedition Wherry

Chesapeake Light Craft (CLC) has a wide collection of small boat plans and kits. The  Expedition Wherry is one example.

CLC's Expedition Wherry by Olav Y. in Stord, Norway

Expedition Wherry using X-Ray vision...

Specifications:

• Length: 18' 3" (5.6 m)
• Beam: 36” (914 mm)
• Weight: 92 lbs. (42 kg)
• Max Payload: 423 lbs. (192 kg)
• Cockpit length: 7’ 6” (2.3 m)
• Water Line Length: 16' 9" (5.1 m)
• Water Line Width: 28" (711 mm)
• WLL/WLW Ratio: 7.2:1
• Hull Speed: 5.5 knots, 10.2 kph, 6.3 mph

From CLC documentation:

“This fast, shapely wherry is intended for serious sliding-seat rowers who are looking for open-water ability and enough payload for camp-cruising.”

Design: “I'm [John Harris, designer of the Expedition Wherry] working within the limitations of a hull design that's really easy to build from a kit.  But I think I got the distribution of volume in the forward third of the boat just right.  It's quite fine down at the waterline, for speed, but with a pronounced 'shoulder' up near the deck to help the bow lift over waves. It's subtle but you can see that feature working in the video footage."

Safety: “Most of the boat is decked in, with only a small "sump" area beneath the oarsman's heels to gather bilge water. An optional Elvstrom-type bailer can dispose of any water that gathers there. There are four separate watertight compartments, all accessible through hatches for gear storage.  The boat has enough stability, and the compartments provide enough buoyancy, that it's possible to climb back into the cockpit after a capsize, bail out, and continue on your way.”

Speed: "At a gentle cruising pace, about 50 percent pressure and 22-23 strokes per minute, you're doing 4.5 knots, or just over five miles per hour. The equivalent of an easy jogging pace on shore. Even with a couple of long breaks, you could cover 30 miles in a day, no problem…The boat is topping out for me around 6.5 knots, or 7-1/2 mph, but I'm not much of an athlete compared to some rowers. A strong oarsman could keep that up for longer than I could!"

Construction: “The Expedition Wherry is a multi-chined plywood boat, with a six-panel hull reinforced by six bulkheads.  The hull is mostly 4 mm Okoume plywood, with fiberglass applied both inside and out.  The computer-cut kit is intricately designed and highly evolved to suit fast and easy construction, including by first-time builders.  Hull panels are snapped together with "puzzle joints," and all of the holes for the temporary wire stitches have been drilled in advance.  Plans builders are provided with full-sized patterns for every part.  An elaborate step-by-step instruction manual, with photos and drawings of every step, accompanies both kits and plans.” 

...Plans overview.

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CLC has produced a video of the Expedition Wherry with the designer, John Harris, rowing and commenting on the boat.

For me, a row cruiser means you can sleep on board. To do that in the Expedition Wherry, a custom sliding seat would need to be built rather than using the Piantedosi unit that CLC recommends. A sliding seat could run on rails attached to the sides of the hull. One could also eliminate the sliding seat and row only with a fixed seat and outriggers.

I would see two alternatives for providing a flat surface for sleeping aboard:

1. Add a folding platform that spans the (approximately) 3’ (0.9 m) between the two waterproof compartments inside the cockpit. While sleeping, your CG (center of gravity) would be above the bottom, but lower than when you are rowing.
   
   
2. Redesign the two compartments (that are inside the cockpit) to provide room to sleep on the bottom (with floorboards), but still maintaining the maximum amount of flotation/storage in the two outer compartments. 

Regardless of which alternative, provision would have to be made for a temporary shelter tent to provide rain protection.

Summary-Pros:

•        A cruising speed of 4.5 mph (7.2 kph) for ten 45" sessions per day results in 34 miles (54 km) a day cruising.
•        Can be rowed with either sliding seat or fixed seat.
•        Designed water-proof compartments for plenty of storage for supplies and emergency flotation.
•        Fully decked and low profile makes her very seaworthy and little affected by cross-winds.
•        Long narrow boats such as this can be car-topped by one person.

Summary-Cons:

•        Some conversion is necessary to make the Expedition Wherry a (sleep-on-board) Oar Cruiser. 

The Expedition Wherry would probably be the fastest of all the oar cruisers we’ve covered in this blog, capable of handling rough water, and with enough capacity to handle at least a week’s worth of supplies and equipment.