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Thread: Ways to rig a cat

  1. #1
    webmaster Michael Strahan's Avatar
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    Default Ways to rig a cat

    Okay, some questions have come up concerning running outboards on catarafts. One person is looking for a way to set up a cat for bear hunting in PWS. I know many of you have done your own rigging, and I think a thread on custom rigs might be appropriate. Let's show each other what we've done and what the possibilities are. What I'm looking for here are photos of different kinds of setups, so if you have something similar to what's already posted, don't worry about the photo. Here are some examples of what I'm talking about:

    1. Cat rigged for whitewater
    2. Cat rigged for fishing / hunting
    3. Small kicker motor on cat
    4. Large outboard on cat
    5. Jet motor on cat
    6. Spotting tower on cat
    7. Half top / full canvas on power cat
    8. Sail rig on cat
    9. ???

    All of these have been done, I just don't have photos of all of them. So how about it, folks? Let's open a discussion on what you can do with a cataraft.

    HERE'S a Link to some power cat pics with large outboards-

    -Mike
    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.
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    Member 6XLeech's Avatar
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    Default Interesting cataraft applications...

    A couple of weeks ago I ran across some interesting powered cat designs on a site, Riverboat Works I think it was, but I can't load the site this AM for some reason. Others:

    14ft cataraft that planes on plywood floor:
    http://www.jpwinc.com/index.php?page=photo&photo_id=167
    If I understand this design, waves coming off each pontoon merge in the middle, which the plywood floor uses for planing?

    Rigging for two inflatable kayaks using rowing seat:
    http://www.jpwinc.com/index.php?page=photo&photo_id=165

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    Member tboehm's Avatar
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    Default

    Quote Originally Posted by 6XLeech View Post
    Rigging for two inflatable kayaks using rowing seat:
    http://www.jpwinc.com/index.php?page=photo&photo_id=165
    Mike I'd be interested on your thoughts about this rig and if you might be able to provide some insights as to its make up especially the seat design. How do you think that this might compare to a Aire traveler set up?

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    Member 6XLeech's Avatar
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    Default Jet cat on Talkeetna - photos?

    1. There's a guide service that runs a 16-18 ft cataraft on the Talkeetna - powered by an outboard (of course) jet. I looked for a picture of their raft - set up for ferrying passengers as I recall, but no pics. Maybe someone else has pics or knows who they are?

    2. Also, in a 2006 post; for rigging a cat to solve frequent dragging problem. Sure sounds intriguing, but again no pics; posted by RussJ in an excellent old tread: http://forums.outdoorsdirectory.com/...ead.php?t=4415

    "The solution I came up with is 1/16” thick HDPE, the same stuff used on airboats (only thinner) to allow them to slide out of the water onto rock beaches. I cut it into two foot wide strips and riveted on both sides ‘D’ rings to coordinate with the ‘D’ rings on the tubes. The HDPE is then attached with cinch straps to the bottom of the tubes. Results are pretty impressive as one person can often slide fully loaded raft, including second occupant, over gravel bars that would require two people and a lot of hard work; or to use an expression from a long gone friend ‘slicker-than-snot-on-a-tit’. When the HDPE is not needed it can be stored in a small roll with a cinch strap around it. The obvious should be noted, draft hasn’t changed and the cat will still hang-up more than the round boat, but at the end of the day the effort to keep the cat going downstream will be a lot less than the round boat."

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    Default

    The interesting thing about that Jacks Plastic catacanoe is the seat is actually a exercise rowing machine. I have the same one, but never thought of using it on a boat. I suppose you would end up with a sliding seat like a racing scull. If the oars are set up right it could be more efficient, but it would not be a stable seat. You could get knocked off that thing really quick.

    The idea of using HDPE skids is another novel concept. Not sure it would be easy to mount it stable enough to be practical though. Personally, I prefer to just float deeper creeks.

  6. #6
    webmaster Michael Strahan's Avatar
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    Default Interesting

    Quote Originally Posted by tboehm View Post
    Mike I'd be interested on your thoughts about this rig and if you might be able to provide some insights as to its make up especially the seat design. How do you think that this might compare to a Aire traveler set up?
    Hi Tom,

    Really hard to identify exactly what is going on with this setup. Looks like regular aluminum tubing with Hollandaer Speed-Rail fittings used to connect it all together. Hollandaers have been used for frames many times before up here. Some prefer them over the NRS fittings because of the weight / bulk reduction. But the problem is that you are forced to use quick-release pins instead of the supplied set screws, which don't provide a reliable grip on a whitewater frame. The problem with the quick-release pins is the they're steel, and they tend to "wow out" the holes drilled in the aluminum pipe over time, and your frame develops some serious rattle. Not a good thing on a hunting trip, as any sounds you make on the river tend to carry clear around the next bend (sound echos a considerable distance over flat surfaces like water).

    As to the seat setup it's hard to say. Looks like a rowing machine or something. I'd have to have better pics to see what's going on with this though.

    It is interesting to see that people are thinking about the catacanoe idea though. Get enough minds working on a problem and who knows what will come up?

    -Mike
    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 Reports on ARK's spray shield setup?

    Greetings,
    I have read pretty near every thread in this great forum regarding powering catarafts with outboards and solutions to avoid spray/cavitation issues, with much interest. I was a whitewater river guide (18' buckets, then bailers) in a past life; now looking for a boat for drift fishing, family float trips, and exploring the islands and inlets off the west coast of Vancouver Island near my home.
    I am considering an Aire Leopard powered by a 25hp Evinrude e-tec (146lbs). Many of you are of the opinion that it is not worth powering catarafts with outboards larger than 9.9, due to the spray/cavitation issues. Others have said this problem can be solved. ARK sells a spray shield set up and 'whale tail' that purports to solve these issues but I can't find much information about its' effectiveness. Can anyone supply firsthand information about their system? Pictures? While we're at it, anyone ever rig one up to sail?

  8. #8

    Default

    bc'er,
    i think the big issues with cavitation and spray were related to jet units on catarafts and trying to power upstream. i'm not entirely sure, so don't call off the dogs on your inquiry. i have seen many outboard prop setups used on cats up to 25 hp. they work well for flatwater and downstream travel on slow, tidally influenced river areas. hope this helps. take care, abel6wt

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    Default

    I used a 30hp outboard with prop on an Aire Cougar (4 tubes). It would get up & scoot, but it was a wet ride.

    I put a solid floor & transom on it, but a lot of water still blew up in the middle and from between the tubes. I cured that by laying down a tarp under the frame that went all the way to the outsides of the boat, and from the front of the frame to the transom I then cut small holes for the straps to hold the frame on top of the tarp. But then I still had a lot of water blowing up from in front of the frame, so I decked the whole front, all the way to the tips, with a sheet of plywood laying across the bow. I still had a little water splashing in front of the tubes that would fly back in our faces occasionally, but that was not nearly as annoying as all the water curling around the outsides of the tubes and blowing into every thing and every one that wasn't directly in the middle of the boat. And there was no way that the guy holding tiller would not still get drenched. It was great fun!

    I also had some issues with cavitation. As long as I kept the stern weighted and the prop very deep it was usually OK, but if there were waves it would still scoop some air. I think the issue I was having was due to all the disturbance of the water between the tubes. There isn't a lot of room down the middle in a four tube cat. A standard cat might be better, but some others complained about the same issue with prop motors. I imagine a jet unit would be worse, but I have no experience with them.

    I'm sure there are ways to get it right, but I ran out of interest when I discovered what great fun whitewater was.

  10. #10
    Member tboehm's Avatar
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    Default pictures Jim?

    Do you have any good pictures of the set up of it?

    You know, I think that between Mike, Jim and Tracy you guys should be able to slove this issue for the rest of us

  11. #11
    Member AlaskaTrueAdventure's Avatar
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    Lightbulb Up on plane...

    tboehm,
    Those three pioneers have already tried to figure out how to get a cataraft up on stop...and have not been totally successful. As long as the inner wakes between the tubes meet and cause water turbulence right in front of the prop or jet drive, it is not gonna work to our satisfaction. Not with todays rafts. Perhaps them guys will design stiff, flat bottomed cataraft tubes that will reduce or eliminate the inner wakes when the boat get up on top of the water.

    Mike...have you and Tracy put a sizable motor on a flat bottomed catacanoe? Did it work any better? Did it work any worse?

    Hey Mike, Yo Tracy....Honestly, I have never figured out if the power traveler experament was cconsidered a partial, or a complete success.
    (I still want one.)

    Dennis
    AK TAGS

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    Default cat on a plane

    I found these pictures of a couple Alaskans planing a cat at Jack's Plastic Welding website. Here is a quote:

    Hi Jack,
    Splashing under power has been a problem is several other of my boats but the front spray guard and the splash flaps performed great!
    I'm working on a "Speed Kit". An aluminum faring that will lift the stern under power and clean up the wake so there will be less spray back there. I have used them on other boats and they work great.


    Anyone up there know these guys?
    Attached Images Attached Images

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    webmaster Michael Strahan's Avatar
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    Thumbs up It was bound to happen...

    Quote Originally Posted by BC'er View Post
    I found these pictures of a couple Alaskans planing a cat at Jack's Plastic Welding website. Here is a quote:

    Hi Jack,
    Splashing under power has been a problem is several other of my boats but the front spray guard and the splash flaps performed great!
    I'm working on a "Speed Kit". An aluminum faring that will lift the stern under power and clean up the wake so there will be less spray back there. I have used them on other boats and they work great.


    Anyone up there know these guys?
    BC,

    Thanks for posting this! The "Holy Grail" of power cats has always been (in my opinion) a system involving modification to the tubes themselves. It looks like JPW has done it. If you look closely at the first photo you posted, you'll see a flange of fabric running from the tube, across the top of the floor. I assume they did the same under the floor. This is what it's going to take to really control the spray issue. Assuming you have a solid floor (not slats where water can shoot through), the only place you'll get spray is between the floor and the tubes. This has always been the problem area.

    Okay, so assuming we're going with welded flanges, here's what's left to do:

    1. Figure out a floor system that's portable for flyout trips. One idea I had was to make a two-layer pvc floor with slats in it for support (the same way Roll-A-Tables are designed). The slats would have to run the length of the floor instead of crossways, because the crossways slats will generate turbulence. Another way would be to make an air mattress for a floor, out of heavy duty PVC.

    2. Figure out an attachment system to connect the floor to the tubes. Lacing would be the simplest, but then you have holes where water will shoot up between them. Another idea is to lace through the floor and the bottom flange, and just velcro the top flange down to the floor.

    3. Look at the feed to the outboard (jet or prop). As the hulls move through the water they generate a wake that converges about 1/3 of the way forward of the transom. This creates an aerated water column aimed right at the lower unit of your motor. If this water column could be mashed down with a skid plate of some kind, it might push the air out of it, to the sides, where it would just trickle out the back.

    Any R&D folks out there that wanna tackle this?

    I believe ARK is going to enter the plastic welding business; I'll talk to Tracey about welding flanges on my Leopard, and I'd be willing to bet that I could run it with a 50 on the back with no problems at all.

    Hat's off to Jack's Plastic Welding for doing this! I believe they're the first.

    -Mike
    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 Kodiak Bearcats

    Glad I could be of some assistance. I, like many of you, have imagined an outboard-powered cataraft that does it all! I did a little more digging and emailed Dave Jones, who sells his custom 'Bearcats' on Kodiak Island. Here is what he had to say:

    I have come to the conclusion that an inflatable cat with typical whitewater tubes is never going to be a speed boat. I have several different boats which have tubes from Jack's and they are great tools. We use them for beaching operations in saltwater applications, often in small surf.
    They haul big loads, are very stable and can't be swamped. Lots of good stuff but speed is not one of them. The soft, collision absorbing characteristics of the tubes is in direct conflict with the rigid planing surface necessary to get any speed out of a boat.

    I have built a rigid bottom inflatable using Jack's tubes and it is entering it's second year of service at my sport fishing lodge. It's powered by a 30 hp (at the pump) jet makes 24 mph (clocked on GPS). It's a neat boat that we use to travel from saltwater up into rivers. This boat is not a cat, it's a mono hull and is not a good boat for beaching in surf. Despite my best efforts, I have been unable to make the perfect boat!.

    Attached are pictures of what I think must be the rigid bottom boat he describes. As you can see, by trying to eliminate the wake issue, he has come full circle to a complete aluminum hull. Still a pretty sweet boat!
    Attached Images Attached Images

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