Building Kayleigh - Part Three

By Terry Lesh - Portland, Oregon - USA

Part I: Hull Construction
Part II: Outfitting
Part III: Performance

Kayleigh : 18' Sharpie Camp Cruiser - Part III: Performance

I was on my way to the 2009 Summer Solstice on the Columbia River near Portland, Oregon, and had stopped at a rest stop. As I got out of the car this little boy (6 or 7 years old) came running up to the boat all excited - "Wow, I really like your boat. That's a real boat!"

Leave it to the spontaneous honesty of children. I wholeheartedly agree with his observation, and authenticity of judgment. Usually the comments of bystanders are more on the order of, "Nice boat, how fast does it go?"

I'll admit she looks fast! Marsh Hawk and I running up the Multnomah Channel on the Columbia River near Portland, Oregon, on an off and on stormy day. Of interest here is my helm position and the universal tiller extension which steers the motor and controls the throttle. She's doing ~ 5.5 mph here, a comfortable speed for the hull and engine. Notice the near perform wave form along the hull - the bow wave attenuated just where the aft twin skegs begin - then the stern wave following the rocker of the aft hull sections. A very gentle wake at this speed. (Pat Patteson)

The Kayleigh design has a maximum hull speed of ~ 6.5 mph with a 6hp engine running @ about ¾ throttle. This is a 1970's two cylinder two cycle outboard engine. I have Doel-Fins on the engine to prevent squatting. More power just results in more squatting with no additional speed. The most comfortable running speed for this hull and engine combination is 5.5 mph, about the speed of the average family cruising sailboat. As discussed in Part II, this is a displacement hull with a lot of rocker and small transom footprint. Stable, smooth riding, rough water capable, but not fast. Fellow Coot buddy, Mark Neuhaus from Portland runs a brand new 6 hp 4 cycle Tohatsu outboard on his sister ship "Turtle."

Getting ready to anchor in a slough off the Multnomah Channel of the Columbia River near Scappoose, Oregon are Kayleighs "Marsh Hawk" on left, and sister ship"Turtle" [not quite finished] on right. In the background is Robin Robinson's fine all weather cruiser [I forget the design name] (Patteson)

We ran side by side at various times comparing the performance of these two boats. I had a much heavier load than Mark did and my hull was immersed at both ends. Turtle, on the other hand had both ends out and she was slightly faster than Marsh Hawk with a lot less wake at comparable speeds. With his Tohatsu single cylinder four stroke motor he also got much fuel mileage than I did. He used somewhat less that 3 gallons for the ~ 60 mile trip, while I used about 6 gallons or so. We were not running very hard since we were trying to save fuel as the current was stronger than we expected and there was no fuel to be had at the closed marinas. When we asked around about this we were told that a lot of the marinas were closed because it was too early in the season, as well as the poor economy. We later learned that some of the large marinas and dealers along the Willamette and Columbia rivers were not making it and had to close permanently. I observed many very expensive yachts in various moorages along the way that appeared to have been abandoned altogether. Millions of dollars worth of boats wasting away.

At this time of year the river was high and current in the channel where we were going upstream was 1.5 - 2 mph. Therefore just to maintain 4 to 5 mph we had to use more throttle for this speed than we figured. In order to estimate how much fuel I would need for this voyage I did several test runs on a lake near where I live to see exactly how much fuel my 6 hp twin two stroke was burning. Using 1 gallon test runs it went for ~ 1 hour and fifteen minutes on a gallon of mix. A little hard to figure since the tanks don't scavenge completely. If my math is correct that equals 0.8 gal/hour. What really surprised me is that it didn't seem to matter what throttle setting I used, it was never less. If I ran full throttle (~ 6.4 mph) it used 1 gal/hr. I was expecting it would burn less at lower throttle settings, like 0.75 or 0.5 gal/hr. That's not a lot fuel, but still disappointing, since Mark's engine must have been using ~ 0.5 gal/hr or less!

As an auxiliary engine I use a 46# thrust Min-Kota Electric mounted on the transom and connected to a 125 amp hour (ah) 12 volt deep cycle battery via a jumper cable. With the jumper cable clamps it is easy to connect to the battery which is located underneath the starboard bunk at the aft cabin bulkhead. I have triple outlet + USB receptacle connected to the battery. From this I run the depth finder, GPS, radios and charging devices along with a computer as needed (I also have small converter available to plug in here). All connectors are the lighter type plugs. To keep the battery charged I use a 1.7 ah /day flexible solar pad on top of the cabin. I never have any battery problems. Wired into the battery and mounted on the aft cabin bulkhead inside is a push-button meter that tells me the state of charge on the battery. I have yet to see it less than "full charge."

The Min-Kota 46 # thrust motor pushes the hull at ~ 3.5 mph at the max setting. I figure I have a maximum of ~ 3 hours battery time (below is a table showing calculations for speed/run-time settings). Theoretically this is enough time and enough speed reserve to get me to a safe place on the river or in the San Juans to iron out problems with the outboard motor. This is the same set up I had on the Baymaster sailboat (previously shown). It saved the day one time at Sucia Island in the San Juans.

We were just outside of Fox Cove when I smelled something hot. I turned around and the outboard was steaming like crazy. We were just at the entrance of the cove and there were many boats about, the mooring dock was packed full and the tidal current was carrying us to the beach. I immediately shut down the outboard, hooked up the electric and managed to maneuver to the dock with it. At the dock I removed the outboard and found a piece of seaweed leaf plastered tight to the water intake. Easy fix and we were back in business. But without the electric auxiliary, problems would have quickly multiplied. You never know when you might need auxiliary power.

To summarize the speed performances for the 6hp twin cylinder two stroke Evinrude Long Shaft outboard in the inboard well of the Kayleigh with ~ 500# payload in calm lake water.

  • Top speed = 6.5 mph.
  • Cruising speed = 5.5 mph.
  • Fuel consumption = ~ .8 gph.
  • Tankage = 4 x 3g tanks
  • Run time / tank = ~ 3.75 hr.
  • Range / tank = ~ 20 mi.
  • Max run time = ~ 15hr.
  • Max range w/o refueling = ~ 75 mi (all estimates are theoretical and conservative)

Those are all nice numbers, making the Kayleigh a very economical boat to run. However these theoretical predictions made on the basis of some tests never quite seem to work out on the water. One can never know for sure how many gallons one has used from those pressure tanks. Further, unless one keeps a dead reckoning account via GPS and gallonage you never know know for sure how far for how long you have been running. I tend to do a lot of poking around and wondering about from any preplotted routes, sometimes back tracking, sometimes stopping etc. All one can do is estimate how much fuel they will need and then stay well within those estimations.

Performance with the Min-Kota as per above conditions:

GPS Measured Speed vs. Estimated Run Time via 100ah Battery @ 50 - 75% discharge:

Measured Speeds are based on average runs in calm lake water.

Speed Setting 5 = 3.4 mph = 1.78 hr
4 = 2.4 " = 2.1 "
3 = 2.2 " = 2.5 "
2 = 1.6 " = 3.07 "
1 = 1.5 = 3.8 "

All my assumptions and calculations are subject to correction. The results of such calculations are theoretical and should be tested in real life conditions on your boat with your motor and battery in your boating environment.

The following pictures are of my Kayleigh ("Marsh Hawk") in various aspects of her performance with comments of what characteristics each photo is intended to demonstrate.

This is the best example of Marsh Hawk's attitude in wind chop running against the river tidal current upon entering the Multnomah Channel from the Columbia River. Note that the sailboat in the background is full & by, while Marsh Hawk's attitude has the bow anti slap pad really doing the breakwater function for which it was designed. This area of the river is the confluence of the channel, the main river and Lake River, just off the downriver point of Sauvies Island. It was stormy that day with winds swirling the compass at ~ 25mph, with currents and waves coming from all directions. While this photo is at one of the calmer spots the angle of the camera does not reveal the wave/trough action. To look at the water from the helm was somewhat unnerving but I was very impressed with the boat's handling characteristics. She was very surefooted, steady in her tracking and quiet. The ride was actually relaxing. (Patteson)
Marsh Hawk and Turtle running upstream in the channel. Note that Turtle is higher on her lines than Marsh Hawk and that the profile of the outboard on Turtle is lower than Marsh Hawk's motor. I raised my motor board from the plan specs to accommodate a long shaft motor, while Mark stuck to the short shaft board measurements. I don't know if this makes any real difference or not, I just feel safer with more free-board in the motor well. (Patteson)
Some parts of the circumnavigation of Sauvie's Island were quite serene and beautiful. Zoom in on this photo and you can see exactly how I have my helm navigation station set up. Here I am also referring to a paper chart clamped to the top of the hatch. The yellow ball at the port side of the transom is an anchor retrieval system. The anchor line is fed through a friction lock fair-lead/guide then through a pulley release system near the ball. To anchor, the anchor and the ball/pulley system is released over board. When the anchor is set, I pull on the inboard end of the rode and the line is locked into position. The ball stays near the boat, just overboard. To pick up the anchor, I pull the ball toward the anchor and it picks up line and the anchor as I approach it. It makes for very easy and safe anchoring off the stern from the cockpit where the anchor is stowed. (Patteson)
Marsh Hawk rafted up with mini-tugs on Fern Ridge Lake near Eugene, Oregon. For size comparison, Marsh Hawk is 18' with a highly rockered flat bottom, low topsides and tucked transom. The tug in the middle ("Sea Weed") is 15', totally freehand designed (no plans) and built by Dick Mitsch from Lebanon, Oregon. The tug to the right on the outside is a Candu EZ design stretched to 18' and built by Dennis Banta from Albany, Oregon. Both tugs are totally flat bottomed with no rocker. The CanduEZ is electric powered. Seaweed has a 6hp outboard in a well. We all have about the same hull speeds. (John Kohnen)
I thought a lot about building a tug before I chose the Kayleigh design. In fact I spent one whole winter redesigning (making it 18' instead of 15') the Bolger Microtrawler, and making a detailed 1' scale model. The real boat would have been 18+ lwl and 8'+ beam and a lot of windage. Comparing the superstructures of the tugs and Marsh Hawk, one can see why they call them "Harbor Tugs". Windage is a big issue when trying to dock or when cruising rivers or the Puget Sound. Another reason why I chose the Kayleigh design. With some regret I chose control over "Chick Appeal." This view also illustrates the "dory" characteristics of the Kayleigh design high clipper bow. Another rough water handling feature. Control features I have added are an extension on the gear control lever of the outboard so I can reach it easily from the helm position; a "monkey stick" steering system [see article on same in Duckworks Magazine]; and a "universal joint" extension handle on the outboard tiller/speed control and a nice folding stool to sit on at the helm. These all serve to make handling easy and comfortable from a sitting helm position. I can reach behind me to control shifting, I can control speed and steering, from anywhere in the cockpit, or I can steer and control speed sitting down at the helm position. (Kohnen)
Marsh Hawk at home in her element, gunkholing in marsh grass on Fern Ridge Lake. She draws 6". The outboard motor prop is no lower than the twin aft skegs (a design feature of the high rocker which allows shallow setting for cavitation plate of the motor). This feature along with the tucked transom and large outboard well opening in the transom allows for safe anchoring from the stern in currents that would not be safe to anchor stern 1st with a planing hull - a white water dory feature. (Kohnen)
Perfect serenity - a dream made real. Reading Sam McKinney's "Reach of Tide" (his gunk-holing exploration of the lower Columbia River) got me hooked on getting a boat with which I could do this same thing. After I got the plans I kept an 8" x 10" copy of the lines drawings by my bed memorizing every detail, figuring out how I was going to do it, and for the year and half it took me to built her I dreamed about this image every night. (Patteson)

(Photo Credits as Noted)

Copyrighted 2010 by Terry Lesh

First E rights to Duckworks Magazine. Others by permission only


To comment on Duckworks articles, please visit our forum