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Thread: How fast will my cat go?

  1. #1
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    Default How fast will my cat go?

    Mike or anyone else, who cares to comment,

    With a 18í Aire Cateraft with a 15 hp 2-stroke, loaded with 1300 pounds including raft, motor, people and equipment, how fast would you expect this boat to run?

    Thanks

    Richard

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    webmaster Michael Strahan's Avatar
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    Default Power Cataraft Speed

    Richard,

    I get about nine MPH tops with my 8-horse, the same boat, and a similar load. I would guess you'll see 12-14 MPH or so. But when you get there, the boat will start producing a wake between the tubes and you'll need to control that or it will flood over your flooring system. Talk to the guys at Alaska Raft and Kayak on this; they have some things that will help.

    Good luck!

    -Mike
    LOST CREEK COMPANY: Specializing in Alaska hunt consultation and planning for do-it-yourself hunts, fully outfitted hunts, and guided hunts.
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  3. #3

    Smile motoring cats

    Mr. Strahan (or anyone that might have a clue),

    Just curious if you (anyone) happen to have a picture of your cat setup with motor? I've attempted (gave up) putting a motor on my Aire Lion raft, the shape of the tubes is not very conductive to motoring at all. In the Tanana I couldn't even get enough power to go upstream with a 40 jet on it, the bow would cause the water to cavitate so badly between the tubes that it would splash back into the boat and almost above the cowling on the motor.

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    webmaster Michael Strahan's Avatar
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    Default Power Cat History part 1

    Catarafts were not originally designed to run outboards; they were intended for whitewater use only. The earliest designs come from Russia, where rigid-hulls were in use for several years before inflatables made their debut in the United States.

    Trying to run an outboard on a cataraft has been problematic for sure. I have been involved on various levels in trying to develop and troubleshoot some of these issues for at least the last fifteen years, on and off.

    The first issue you have to decide is the size and type of motor you want to run. My needs may not be the same as yours. Iím attaching a photo of the transom I use, as you requested. In my situation I am not trying to go upstream at all, but need only to make faster time downriver on long floats. My longest guided float to date was the Dishna, where I managed 180 miles in fourteen days. Having the outboard along made this trip possible and gave us plenty of hunting time. We simply motored from one hotspot to another until we shot our moose, then the rest of the trip was a boat ride. This is an adjustable transom made by Sea Dog (no longer available, but there are others), and I run it with an 8-horse Yamaha two stroke. The outboard is very quiet and an excellent choice for hunting. I have even backpacked this outboard several miles to get to rivers that were otherwise inaccessible.
    LOST CREEK COMPANY: Specializing in Alaska hunt consultation and planning for do-it-yourself hunts, fully outfitted hunts, and guided hunts.
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    webmaster Michael Strahan's Avatar
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    Default Part 2

    Here is a close-up of the transom I use, mounted on my 18í AIRE Leopard cataraft. I can adjust this transom on-the-fly while Iím motoring (though I would not recommend it for safety reasons). If you go with a setup like this, you will want a seat on the back of your frame or perhaps a longer tiller handle. I have used a long stick duct-taped to the tiller handle and this allowed me to operate the throttle nicely. With this setup I can operate the outboard from near the oarsmanís seat area, however it works better for me if Iím sitting on the port-side tube.
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    LOST CREEK COMPANY: Specializing in Alaska hunt consultation and planning for do-it-yourself hunts, fully outfitted hunts, and guided hunts.
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    Mob: 1 (907) 229-4501
    "Dream big, and dare to fail." -Norman Vaughan
    "I have climbed my mountain, but I must still live my life." - Tenzig Norgay

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    Default Part 3

    Some of the earliest experiments I was involved with were on area lakes, where we continued to test cats for several years. This photo was taken on Skilak Lake, out on the Kenai Peninsula. I am in the lead boat, which is one of the old AIRE Cougars, and the trailing boat is a friend of mine in an AIRE Rivercat (no longer made). Both boats are running 25-horse outboards. Mine was running a long shaft and the other was a short shaft. We swapped motors, moved loads around, etc, but the best performance we got was with very light loads (one person). At the time, there were no inflatable cats available with a gradual bow transition like the Leopard has nowadays. All of AIREís boats had a hard miter seam where the bow transition started. Our biggest problem was controlling the spray generated when this bow section met oncoming waves. We got soaked. So for these pictures you can see we have the seam out of the water. Thatís what we had to do to keep from getting wet. Well, obviously this would not work for most situations, so we went back to the drawing board.
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    LOST CREEK COMPANY: Specializing in Alaska hunt consultation and planning for do-it-yourself hunts, fully outfitted hunts, and guided hunts.
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    "Dream big, and dare to fail." -Norman Vaughan
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    Default Part 4

    We continued studying the spray issue and found that unless we could come up with a gradual bow transition, it was not going to work. I suggested that we have AIRE build some custom tubes with a gradual bow transition, but my partner in crime said that it would be impossible to get the material to make those kinds of curves; the math was too complex and such a design would be prohibitively expensive. Well, guess what? AIRE found a way to make it happen, and now ALL of their cats are made this way. So with that problem corrected, we went on to other issues and even larger outboards. But we discovered that the problems were just starting. The tubes, when pushed through the water at speeds more than about 9-10 MPH, generate a wake that converges about Ĺ to 2/3 back from the bow section. This forms a rooster tail that aims right at the driver. Trust me, I was sprayed many times this way. We tried all sorts of ways to deal with this, from spray shields, to full-length plastic (UMHW), and even aluminum was discussed. All of these setups were extremely complex to build, and very expensive.

    The other issue we had was the transom. We wanted something that would run a jet and a prop, and it was nothing but trouble. We found that we could somewhat control the rooster tail effect by mashing it down with a good skid plate under the frame. But the water was somewhat aereated and though the prop worked, the jet was literally sucking wind.

    In addition to that, we reasoned that we needed more floatation, because some folks would be running this boat with big loads, and the smaller cats just werenít cutting it with the spray issue, etc. About that time AIRE came up with a new cat, the Super Leopard. This was a hybrid between the original Rivercat and the Leopard. Basically it was a Leopard with a smaller inner sponson attached along the inside edges of the tube. It added a huge weight capacity to the boat, but created additional problems with water spraying up between the sponson and the main tubes. For the record, these tubes are no longer made by AIRE. Someone may get lucky and get them to make a set, but it would be by special arrangement only if they did it at all. The Super Leopard was a nice boat and it was a shame to see it go. But it was prohibitively expensive and only a few were ever made. Hereís a photo of a Super Leopard with a 35-horse prop on the back.
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    LOST CREEK COMPANY: Specializing in Alaska hunt consultation and planning for do-it-yourself hunts, fully outfitted hunts, and guided hunts.
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    "Dream big, and dare to fail." -Norman Vaughan
    "I have climbed my mountain, but I must still live my life." - Tenzig Norgay

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    Default Part 5

    These larger outboards require a fixed-height transom, as opposed to the smaller setups like the one I use. We had several sets of custom tubes built by AIRE, because there were lodges and government agencies that wanted something they could fly out with and use in remote locations. Some of these boats required a huge amount of labor in construction and testing on local lakes, and few of them really worked as they were supposed to. The biggest one we built ran an 88-horse prop. We tested it on Wasilla Lake and it worked fine with the loads we had aboard, but we still had a spray issue with heavy loads. I saw one of these boats this winter up in Fairbanks and was surprised that it was still being used. Here’s a photo of it in the parking lot at Pike’s Landing. It was sort of a strange reunion, and I never did see the owner, though I would have loved to talk with him about how it was working out.
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    LOST CREEK COMPANY: Specializing in Alaska hunt consultation and planning for do-it-yourself hunts, fully outfitted hunts, and guided hunts.
    CLICK HERE to send me a private message.
    Web Address: http://alaskaoutdoorssupersite.com/hunt-planner/
    Mob: 1 (907) 229-4501
    "Dream big, and dare to fail." -Norman Vaughan
    "I have climbed my mountain, but I must still live my life." - Tenzig Norgay

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    Default Part 6

    About the time this photo was taken I started pulling away from my involvement with the company that was making these setups (for personal reasons). There were some differences of opinion as to which direction to take with this, as nothing we were trying was really working. I wanted a simple solution that would work on any cat, with any outboard, jet or prop. It just wasn’t happening. My associate kept building these setups and they got more and more complex and expensive. Most of them came back to him because they just didn’t work very well. Many of the owners of these boats spent a lot of their personal time doing R&D work on them that should have been done prior to them taking delivery. Here’s a photo of one of the boats in construction. As you can see, the frame has become incredibly complex.
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    LOST CREEK COMPANY: Specializing in Alaska hunt consultation and planning for do-it-yourself hunts, fully outfitted hunts, and guided hunts.
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    Web Address: http://alaskaoutdoorssupersite.com/hunt-planner/
    Mob: 1 (907) 229-4501
    "Dream big, and dare to fail." -Norman Vaughan
    "I have climbed my mountain, but I must still live my life." - Tenzig Norgay

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    Default Part 7

    Hereís an image of the transom area on the same boat. Each of these boats was a custom build, and no blueprints were saved.
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    LOST CREEK COMPANY: Specializing in Alaska hunt consultation and planning for do-it-yourself hunts, fully outfitted hunts, and guided hunts.
    CLICK HERE to send me a private message.
    Web Address: http://alaskaoutdoorssupersite.com/hunt-planner/
    Mob: 1 (907) 229-4501
    "Dream big, and dare to fail." -Norman Vaughan
    "I have climbed my mountain, but I must still live my life." - Tenzig Norgay

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    Default Part 8

    Here are some details of the floor support system; again, this didnít work well because it was just too complicated and expensive to build. By the time things got to this level of complexity, I feel that the vision of building something for the average guy who just wants a lightweight, break-down hunting boat to take on flyout trips was lost. These boats were highly specialized and all but useless to most of us.
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    LOST CREEK COMPANY: Specializing in Alaska hunt consultation and planning for do-it-yourself hunts, fully outfitted hunts, and guided hunts.
    CLICK HERE to send me a private message.
    Web Address: http://alaskaoutdoorssupersite.com/hunt-planner/
    Mob: 1 (907) 229-4501
    "Dream big, and dare to fail." -Norman Vaughan
    "I have climbed my mountain, but I must still live my life." - Tenzig Norgay

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    Default Part 9- done at last!

    Here is a final shot of the bow section. Itís made of UMHW plastic. I believe this is not what most folks want.

    Well, so much for the history lesson. The main reason I mention this stuff is to point out that this is a very complex process. Not to discourage you at all, but you need to know that itís not merely a matter of finding the right transom and slapping something together in your garage. I say that knowing that there are some brainiacs out there who probaby have an elegant, simple solution to this just waiting to come out. The first Apple computer was built in a garage, so why not?

    I believe it can be done, but the designs I showed you are not it. At least not for boats with outboards above 15 horses. I have some ideas, and hope one day to make them commercially available. Time will tell.

    Good luck with your project, and I hope you will post the results here!

    Have a great winter!

    -Mike
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    LOST CREEK COMPANY: Specializing in Alaska hunt consultation and planning for do-it-yourself hunts, fully outfitted hunts, and guided hunts.
    CLICK HERE to send me a private message.
    Web Address: http://alaskaoutdoorssupersite.com/hunt-planner/
    Mob: 1 (907) 229-4501
    "Dream big, and dare to fail." -Norman Vaughan
    "I have climbed my mountain, but I must still live my life." - Tenzig Norgay

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    Default My attempt at power boating a cat

    I'm glad you posted all this Michael. I remember watching the progression of the designs as you guys were doing this. This was a great review, and you filled in several things that I was not aware of. Thank you for sharing.

    About the same time as you were experimenting, I tried to do this in a more simple fashion with my Cougar. Primarily because I had no money for a retrofit, or a new boat. I built a plywood "floor" that sloped down from the front of the primary section of the frame, back to the bottom of the transom. This floor, of course was only 8' long, so it was rather steep, but it did work -- sort of.

    I used a 30 hp outboard, and it would get up on step with a fairly light load, but had cavitation issues unless I added weight. But then I couldn't get it up with only 30 hp. I finally resorted to buying a brass prop with the flattest pitch I could find (13"), and had that flattened out to 11" at a local prop shop. This actually worked great. It wouldn't go as fast, but it would pull a medium load out of the water in a hurry. I even pulled water skiers with it on Nancy Lake.

    Like you, I did manage to flatted the central rooster tail with the floor, but the issue I could never solve well was the spray from everywhere else. The hard transitional rise of the early Cougar tubes would throw lots of spray in front, so I laid down a sheet of plywood across the tubes at the bow. That worked pretty well, but then I got soaked from the spray coming up from the sides of the floor. So I covered the whole top of the frame with a poly tarp. That seemed to work, but now I couldn't get my feet down to row when needed, and I still got considerable spray that wrapped around from the outside of the tubes and soaked everything on the back half of the boat, which meant that the driver needed a dry suit.

    That was about the time I got seriously interested in real whitewater rafting, so I bagged the whole idea and started making the boat lighter, not heavier.

    Like you, I think there might be simple solution to this, but I never got mine sorted out. It was fun playing with it though.

  14. #14
    webmaster Michael Strahan's Avatar
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    Thumbs up Thanks, Jim!

    Quote Originally Posted by Jim Strutz View Post
    I'm glad you posted all this Michael. I remember watching the progression of the designs as you guys were doing this. This was a great review, and you filled in several things that I was not aware of. Thank you for sharing.

    About the same time as you were experimenting, I tried to do this in a more simple fashion with my Cougar. Primarily because I had no money for a retrofit, or a new boat. I built a plywood "floor" that sloped down from the front of the primary section of the frame, back to the bottom of the transom. This floor, of course was only 8' long, so it was rather steep, but it did work -- sort of.

    I used a 30 hp outboard, and it would get up on step with a fairly light load, but had cavitation issues unless I added weight. But then I couldn't get it up with only 30 hp. I finally resorted to buying a brass prop with the flattest pitch I could find (13"), and had that flattened out to 11" at a local prop shop. This actually worked great. It wouldn't go as fast, but it would pull a medium load out of the water in a hurry. I even pulled water skiers with it on Nancy Lake.

    Like you, I did manage to flatted the central rooster tail with the floor, but the issue I could never solve well was the spray from everywhere else. The hard transitional rise of the early Cougar tubes would throw lots of spray in front, so I laid down a sheet of plywood across the tubes at the bow. That worked pretty well, but then I got soaked from the spray coming up from the sides of the floor. So I covered the whole top of the frame with a poly tarp. That seemed to work, but now I couldn't get my feet down to row when needed, and I still got considerable spray that wrapped around from the outside of the tubes and soaked everything on the back half of the boat, which meant that the driver needed a dry suit.

    That was about the time I got seriously interested in real whitewater rafting, so I bagged the whole idea and started making the boat lighter, not heavier.

    Like you, I think there might be simple solution to this, but I never got mine sorted out. It was fun playing with it though.
    Jim,

    I too have been following your exploits with interest! Though we haven't been on the river together yet (a situation I hope we can remedy), I have heard a lot about you and have the highest respect. I've seen your posts on the KCK listserver (any chance we can get them to merge with this site?)

    I chuckled at some of your experiments, because they mirrored some of our own. We, like you, attempted to flatten out that hard miter up front but we used UMHW plastic instead of wood. Ours looked like an armadillo when we were done, and it didn't work very well at all. Then AIRE redesigned the tubes and it was a moot point. Still, it seems we traveled the same path, and have both received numerous showers in the process. In the end, I ended up really clean, but not much closer to a solution.

    Having said that, I am gratified to know that many of these boats did work for people. My favorite one was a Leopard that ended up with full floorboards, remote steering up front, a bow cover, and a half-top. The guy had it built for saltwater fishing I think out of Seward. It was a beautiful boat, but I haven't seen it since, and have no photos of it.

    I still believe there is a way to do this, and I think I know how. But it will take some money to prototype it all out. If successful, I believe it will blow the sportboat market apart.

    I hope all those shade-tree mechanics out there will keep playing with this. There are ways to make it work; it's just coming up with that magic bullet...

    I'm attaching a photo of one of the big cats. This might be the same boat I saw in Fairbanks this winter. The tubes were 22' long, if I remember correctly. Custom built by AIRE. I can still hear the growl of that 88-horse outboard. What a machine.

    Thanks for the kind words, Jim.

    Regards,

    -Mike
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    LOST CREEK COMPANY: Specializing in Alaska hunt consultation and planning for do-it-yourself hunts, fully outfitted hunts, and guided hunts.
    CLICK HERE to send me a private message.
    Web Address: http://alaskaoutdoorssupersite.com/hunt-planner/
    Mob: 1 (907) 229-4501
    "Dream big, and dare to fail." -Norman Vaughan
    "I have climbed my mountain, but I must still live my life." - Tenzig Norgay

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    Unhappy Exact answer 2 inquiry

    Quote Originally Posted by Richard Ragan View Post
    Mike or anyone else, who cares to comment,

    With a 18í Aire Cateraft with a 15 hp 2-stroke, loaded with 1300 pounds including raft, motor, people and equipment, how fast would you expect this boat to run?

    Thanks

    Richard
    9-11 knots!!!! max throttle & 10 knots backed off throttle just a bit. That's it!!!

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    Default

    Their is a guy in North Pole that had a Leopard with a 90 Merc with a jet on it and said it ran like a champ. He built it to run up the Salcha and said he could go where the river boats couldn't.

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