Flyfishing kick boat cat

@portacruise

great comments

I’m gonna 2x on making the amas removable. I did it on a boat with outriggers. And essentially, these toons are outriggers.

of course, the amas need to carry the person, so would be much more substantial, but this setup cries for a Wharram or other simpler lashing. The toons get built and then the amas can be carried together with a trapeze or some other way and they can be lashed here in 4 places per ama. I used cheap rubber lashings from a waste tractor tube and keep a couple around as they will degrade over a couple years in direct sun.

But this also means the toons don’t need garboards and the thing is far more portable..

Here in Minnesota, you’d want that for carry in lakes and it looks too heavy all together.

 

Thanks for the comments ☺️

Seems like it's going to be foolish to give up now and foolish to carry on so I'll do the latter.

The pontoons currently weigh 4.2kg each. So I'm hoping to keep it below 15kg total for the boat but I'm going to have to be careful to achieve that! I must select everything according to weight. I will take a look at the wharram lashing approach. Thanks! It will definitely be able to be taken apart easily. I have aluminium 25x50mm sections for the cross beams and will laminate a hollow core central seat platform from 4mm ply and glass sandwich. I did some tests and it's super strong and light. I might invest in some carbon fiber braided tube and vacuum bag that onto super lightweight japanese cedar for the cross beams but that might just be a lot of effort for little savings on the weight over the aluminium.

So far I've just got both hulls to the same point with the bulkheads laminated with 2 layers of biaxial 30oz cloth on each side of each bulkhead. One piece on each side cut on the bias and the other not. It feels very strong! And all the seams are now taped inside. I'll move onto glueing some strips of spruce or meranti to the insides of the fore and aft closed sections so there is wider landing for the decks to glue on and laminate the decks insides with light glass and epoxy. Still not sure if I need to glass the insides of those or not.

For power I'm going to get a little 18lbs water snake. Only weighs a little over 2kg. Should be strong enough given the size of the boat. I don't need to go fast.

 

Don't forget about the weight of the battery for your water snake motor, which could be another 20 kg depending on whether you use lithium or not, and how far you will be going. For me, a drill motor setup has been a lot lighter and much more versatile compared to a traditional design troll motor.
Here's a link to one possible set up of a drill motor , and there are also other different ways to set things up.



Myself always motors into the opposing forces on my fishing trips, that way I can Coast back with minor steering forces, and not get stranded, should there be a loss of power. That means launching into the wind and waves on open water or Upstream against river currents. Possibility of quickly attaching back straps to the inflated setup / Portaging up or down and around River Rapids, thanks to the built-in zipper compartment pockets which will keep equipment and supplies in place. Looks like the first picture in your post #28, but I sit 20 cm above the water surface . There's also an advantage in having the Lays all to myself because almost all of the smaller craft like kayaks, canoes, Etc, will move themselves downstream with the forces or be blocked off. That's because rarely will they have enough energy to challenge the forces, rapids, or thin water using paddles or fins due to their much heavier weight plus limited dragging terrain. That's compared to Stepping or climbing around with a back strapped float tube. Most of the casting is done from good Shoreline or shallow water, knee deep or less standing up; sit down position is mostly used for trolling. Another Advantage of going Upstream on Rivers is it gives a preview of where the hazards and lays may be for working the drift back down toward the launch exit.

I use a foot bar for mounting the drill propeller shaft swivel instead of a transom shown above in some of my setups. A mouth tube which attaches to the different accessible valve nipples is used to adjust pressure for altitude, temperature, and ergonomic comfort. Punctures and leaks have all been small over many decades and have not required immediate repair. Pressure is restored with the mouth tube remaining attached while underway, and the trip is continued. When I'm ready to come back to shore, repairs can be made and tested overnight.

The whole FT setup including propulsion, equipment, snacks and 1 L of water weighs under 14 kg and most of it can be packed down into 1 carry-on bag when deflated and empty. So that compactness has allowed me to travel by air with the set up, visiting/ exploring hundreds of water places throughout the USA, over the many years. Probably boring to most people, but it has been a lot of fun for me anyway. Ha..

 

Some progress after another extended hiatus.

The decks are on. I glassed out the inside and glued on some internal stringers around a half inch square to form a larger landing area for the decks, rasped and sanded the correct angle onto them them to fit the decks nicely and then glued the decks on with thickened epoxy and strapped them down with lots of buff tape wrappings. It seemed to all go smoothly.

The foam insets in the central recessed areas are glued in place with thickened epoxy. Those areas will need to be glassed for strength and waterproofing. Not pictured, but I also stiffened the gunnel area in the center recesses with some 1/4 inch ash and will add some more traditional gunnels in that area mostly for the purpose of creating some lashing points for tying on gear. I have thought long about how to attach the seat frame to the pontoons and have decided the best method will be to lash them directly to the gunnels or possibly to drainage holes further down that will drain the central parts as they will be just above the waterline by my rough load testing. It feels very strong and I'm sure as it is it would easily support my weight. I can also make the seat frame a bit narrower than the recessed area to allow some trimming of the weight fore and aft should it be necessary by simple moving the lashings along the gunnels. for the seat frame ive got some nice pieces of Douglas fir and 3/8" ply to glue up. The fir is stronger and lighter than the aluminium I originally bought for the purpose.
I have been considering just not glassing as it will possibly save weight. Not sure on that though. Just paint on some epoxy to seal it and followed by few coats of some sort of twin pack paint. I might regret that later... This boat will however spend the majority of its life stored in a dry shed so I'm not sure that glass will be necessary. I am sure it will be better to glass it but I'm not sure about the weight. possibly it would be lighter and use less resin with glass rather than just a rolled on resin for waterproofing. I'm not overly concerned about getting a perfect finish at this point. Just a nice functional painted surface will be just fine!

I am now racing against the clock as I have a trip planned for the 24th of May to a little lake and would love the boat to be ready for her maiden voyage by then.

Thoughts comments or any other related advice would be gladly appreciated!

 

Thanks for posting, that looks like good work with the pontoon hulls!

Wonder if your boat will be transported to water in already assembled form (using car top, trailer, Etc), which might save a lot of fishing time and annoyances? Going back and forth for parts, cargo, and the propulsion assembly, while possibly having to block the launch ramp might be some considerations. Depending on what kind of water you have and what the launch points are like, Small detachable Wheels might help with moving the completely loaded boat in one move to the water launch site. Basically like moving a wheelbarrow from vehicle to Launch site, I have made some of these with a single balloon wheel, but two wheels are more stable, though usually heavier. Or a vehicle trailer can be used to speed things up. If you can make the seat as adjustable (back and forth) as possible that might also help , since usually the cargo load does not balance at exactly the same point, each time. Also an adjustable seat with back, that tilts forward/back Plus lowers/ raises will help with the ergonomic comfort especially when it's an all-day trip.

Here's a link to a Hobie pontoon kick boat manual ( float cat is no longer made), might give some idea about oarlock placement; adding a foot bar to push against might help increase the leverage, Power and range that can be delivered.

HOBIE FLOAT CAT 75 ASSEMBLY AND OPERATION MANUAL Pdf Download https://www.manualslib.com/manual/772246/Hobie-Float-Cat-75.html

Hope this helps! Of course it may not work for your situation, so feel free to discard, ha!

Ps. A few decades back, I made a pontoon boat from closed cell polystyrene foam with the two poly 1.8 meter hulls, separated and bolted together with three threaded approximate 1.2 cm SS rods. Then a low profile folding aluminum sand chair seat was attached, just for grins. It was very lightweight, worked great for what it was. But the blunt ends required a lot more energy for propulsion, compared to using something with kayak shaped hulls.

 

Hi. Thanks for the ideas. I plan to mostly use flippers for propulsion but the oars sound like a good idea. I'll play around with that. But also long term a 18lbs water snake trolling motor and lithium battery.

That hobie user manual is super useful. Thanks for that. My goal is to get her at least watertight and floating by the 24th and do some testing at a small and reasonably safe dam I'm planning on visiting for some fishing. I've pretty much glassed the whole boat now. Just need to do the decks.

I might well just transport it assembled on the roof. I have not even checked if the ponts will fit in the back of my car. They might do.

 

She floats! Overall very successful and only a few minor issues to attend to. Mostly that one side was taking on water and the actual water line is basically right on the holes I drilled through to lash on the seat frame. Compared to my old blow up belly boat she is a pleasure to fish off. Fast and a lot less effort to get around. I'm high and dry. The stability is superb. It would take quite a lot to flip it.



The lashing of the seat frame to the hulls is time consuming. I'll try to come up with an easier solution that is faster.

The holes for the lashings are basically only marginally higher than the waterline. I believe part of the problem is that since I designed and started building this boat I might have gained some weight lol. That and the build was a little over engineered. I could have used 3mm ply and been a bit more careful in the construction to keep the weight down. She is not terribly heavy but it'd be better if she was a bit lighter.

I'm planning to plug those lashing holes, raise the central decks or storage areas around 30mm and then work on some storage and rod holders on the seat frame... Then obviously paint and stuff to finish her off.

Overall I am super pleased with how she worked.

 

Thanks for posting comments and pics! Beautiful and functional looking setup, congrats!

Amount of freeboard is good news / bad news for the intended purpose of these types of kickboats. Myself usually prefers to err on the side of larger numbers, because of the limitations to accommodate additional loads, without the hazard of submerging the pontoons. Motor, battery, anchor, tackle, tools, snacks, water, etc. might have to be added depending on how far and how long someone will be out. Increasing chop might mean a wet ride from splashed in water; putting drain holes in the seat may help so someone doesn't have to sit in a puddle marinating. Unless one be using waders. OTOH low freeboard helps when fighting against windage.

If these turn out to be considerations, mounting the seat higher and spreading the pontoons wider might help with stability and maybe a dryer ride.

On my inflatable version, I can change the freeboard to a certain degree, by adding or removing air @ the pontoons plus the balloon seat bottom and back. That way, I can sit lower when riding rapids and higher when catching a tailwind.

Hope this helps, but may not work for your particular excursions. So feel free to discard!

 

Replace the holes with 3" or 4" nylon cleats mounted horizontally preferably with two legs. Tie a piece of line through one of the legs or around the body of the cleat. It will be much quicker to wind the line around the cleat and the beam a few turns and then cleat the end of the line.
It's a nice looking rig, hope you get a lot of joy from using it.

 

One Thing to keep in mind is that streamlined kick boats are not necessarily faster than round ones, because of the possible increase of surface area friction. Particularly at very low speeds which would be case for fin propulsion.

Are Longer Kayaks Really https://guillemot-kayaks.com/sea-kayak-recreational-kayak/petrel-play-petrel/are-longer-kayaks-really-faster?fbclid=IwAR2_2IYYTFuNvpSi4p0I4QVclTaaorowdczF8Mofk10dj9B9-S4hBY4UJtg

From the link:

"If you were to take the drag number where the magenta curve crosses the 2 mph line and slide left to where that level crosses the green design optimized for 7 mph you will see that for the amount of effort it takes to make the 4.7' long boat go 2 mph you the 17.7' long 7-mph boat would only be going about 1.4 mph. The lower wetted surface area of the short boat is sufficient to make up for the fact that it will make a bigger wake at higher speeds."

But of course streamline shapes or more pleasant to the eye, and better at cutting through waves or chop, so long as they are continuously pointed into the forces.

 

Thanks! Great idea! I was thinking of doing exactly that. It doesn't actually need much to keep the whole thing together.

I got some rather overpriced fairing compound compatible with the epoxy so I'm going to make some changes to the hulls them fair and paint them.

Thanks for all the helpful comments.