Sunday, April 17, 2016

An Easy-to-Build Oar Cruiser


An Oar Cruiser based on a simple to build canoe.

Quick Canoe (built and photo by Rick Landreville)

Overview of lines (Source)

Quick Canoe model as an Oar Cruiser showing flotation



Quick Canoe model as an Oar Cruiser


Specifications of Quick Canoe as Designed by Michael Storer:

  • Length: 15' 6" (4.7 m)
  • Beam: 33" (838 mm)
  • Weight: 45 pounds (23 kg)
  • Water Line Length: 15' 6" (4.7 m)
  • Water Line Width: 29" (737 mm)
  • WLL/WLW Ratio: 6.4:1
  • Hull Speed: 5.3 knots, 9.8 kph, 6.1 mph

Conversion to an Oar Cruiser:

  • Lengthened the hull by about 6.5% to make the overall hull 16' 8".
  • Note: The only design change from Storer's plans (below the water line) is the increased length. That change in water line length has very little impact on her Hull Speed (2% faster) and therefore, If I were to build the boat, I would NOT increase the length as I did in this model.
  • Reduced the length of the two stems from 18.7" (474 mm) to 7" (178 mm). Increased the width of the side panels at midships by 2" (51 mm). Drew a new sheer line through these 3 points resulting in a reverse sheer line.
  • Added bulkheads with large access hatches approximately 4.5' (1219 mm) inside the two stems. This created an internal cockpit approximately 7' (2134 mm) long.
  • Added full-length cross-slatted floor boards to provide a sleeping platform and anchors for movable foot braces and rowing seat.
  • Added full decking with a cockpit opening 5' (1524 mm) long by 24" (610) wide. The deck is 4' (1219 mm) wide midships (extending 7.5" [191mm] beyond the topsides), tapering at the bow and stern.
  • Added a coaming around the cockpit opening 5" (127 mm) high at the forward end sloping back to 3" (76 mm) high at the aft end.
  • Added oar lock pads to the extended deck to provide an 8' span.
  • Added a fairlead and 6" (152 mm) cleat to the deck for anchoring (See "Anchoring" in this blog).
  • Added reverse reading compass just aft of the coaming.
  • Added 7 pool noodles (12" by 3.5", 305 mm by 89 mm) to each side of the hull under the side decking. This provides 29 pounds (13.2 kg) of floatation on each side of the hull, making re-boarding after a capsize easier.

Specifications of Quick Canoe as an Oar Cruiser:

  • Length: 16' 8" (5.1 m) (See note above)
  • Beam at the midships deck extension: 47" (1194 mm)
  • Beam at top of hull: 33" (838 mm)
  • Estimated Weight: 75 pounds (34 kg) due to decking and bulkheads
  • Water Line Length: 16' 3" (5 m)
  • Water Line Width: 29" (737 mm)
  • WLL/WLW Ratio: 6.7:1
  • Hull Speed: 5.4 knots, 10.0 kph, 6.2 mph

Summary-Pros:

  • Easy to build.
  • She would be fast due to her high WLL/WLW Ratio of 6.7:1.
  • The full deck, high coaming and flotation on each side would all help to make her more capable in heavy weather.
  • The reverse sheer reduces windage (at the ends) and adds a little freeboard at the cockpit.
  • The two water-proof compartments provide room for dry storage of supplies and equipment as well as emergency flotation.

Summary-Cons:

  • The narrow hull makes her more tender.

Re-boarding an Oar Cruiser:

He wasn't stupid; he just didn't think. It was late fall. No other boats in sight. Rather than get his 'pee-bottle' out, he just stood up and relieved himself over the side; lost his balance and fell overboard. He was in his Quick Canoe Oar Cruiser. (The flotation under the side decks would not support all his weight, but they would help.)

First, he pulled the oarlock out of the socket (both oarlocks and oars were tied to the coaming with light line). Holding the gunnel at the back end of the cockpit, he lay in the water on his side, parallel to the gunnel with his feet toward the other end of the cockpit. He then hooked his top leg over the gunnel and quickly rolled into the cockpit, ending up on his back in the middle of the boat. During the roll-in, more water came over the gunnel. He took his bailing scoop and without sitting up, scooped out as much water as he could. He wanted to keep his weight as low as possible because most water-filled boats are very unstable. After he got most of the water out, he used his big sponge (also tied to the boat) to get the last of the water out and vowed, "Never again…"

(Thanks to John Welsford for this technique of re-boarding)






5 comments:

  1. This post makes such a message: the essence of the oar cruising are oars not hulls. Nice job. Thanks, Tom and Paul.

    ReplyDelete
  2. Hi Wojtek... To use a 'car' analogy, the oars (and oar locks, seat and the relationship among them) are the 'drive train', the boat is the body and frame, and we are the engine...
    The surprising thing for me was how effortless (relatively) it was to row the flat bottom hull, essentially a 'sharpie' hull. I think the key to easily driven hulls is a high waterline length to waterline width ratio, at least 6:1 AND light weight AND low windage, especially at the ends... Now add sleeping capability and we have an oar cruiser... All the other stuff is just refinement... OMHO

    ReplyDelete
  3. If you search for sawfish kayak, you will find my kayak design, built out of foam. 12 feet long, 28 inches wide, 23 pounds.
    I created it for my parents as they cannot handle the weight of their plastic kayaks anymore.
    I'm a rower at heart and am designing a pulling boat in foam in my head.
    I plan on construction this winter.
    I'm torn between a guide boat, and an easier to build shape.
    I'm not so much into overnight trips, but love your blog.

    ReplyDelete
    Replies
    1. When I read your article on the sawfish kayak, it got me to thinking of using your Skin On Foam (SOF) technique for an oar cruiser... light, unsinkable, custom designed any way you want, warm in the winter for on-board sleeping, inexpensive (relatively)... Hmmmm.
      Tom

      Delete
  4. If you search for sawfish kayak, you will find my kayak design, built out of foam. 12 feet long, 28 inches wide, 23 pounds.
    I created it for my parents as they cannot handle the weight of their plastic kayaks anymore.
    I'm a rower at heart and am designing a pulling boat in foam in my head.
    I plan on construction this winter.
    I'm torn between a guide boat, and an easier to build shape.
    I'm not so much into overnight trips, but love your blog.

    ReplyDelete