RebelCat 5 - The Cat
I love Most
After RebelCat 4, there was still a cat missing - the one
that anyone could make. Nobody was going to make a RebelCat 4 - it was huge,
complex... in short, it was simply beyond most people's
ability. So now it was time to go back to those 10-inch pipes
and make the cat I had started BEFORE I saw Waterworld and got
'inspired'. I documented the whole adventure. Here it is...
Look familiar? Starting RebelCat 5 in the same way as 4,
because I found it to be logical. I first find the place I want
to sit on the cat, then design the deck and the rest of the cat
around me. Here, just like on RC 4, I'm sitting over the water.
At this point, I'm still 'feeling' how the cat will evolve -
nothing is decided.
Now that I know what I want, I start creating the deck
frame. It will be wide enough for two adults side by side on
This is new - storage under the deck covers. It's perfect,
because it's the best place for weight on the cat - in the
Exterior latex paint, four coats, has worked really well. No
more boat resin on these parts. Sun and water have not affected
The wooden parts of the deck are done. The aft spreader and
rudder are coming along. These pipes, which I've had now for a
long time, will not be on the finished cat. They are just
really convenient as a base for building the cat. The cat's
pipes are in the background.
Unusual for a cat, a pivoting centerboard, and it works
phenomenally well. It tucks up under the deck when launching
and beaching and can be set in five positions.
Sealing the rudder and centerboard with some boat resin I
had leftover. Epoxy resin is not as smelly as polyester.
This pontoon bow has just been heat-shaped, and the
overlapping PVC pieces coated with glue. The weight holds the
two flaps together until the glue dries.
Heat-shaping is a technique I developed while making
RebelCat 4. It was so successful at creating wedge-shaped,
wave-piercing bows on the pontoons that I have advanced the
technique for RebelCat 5. You have to see this cat gliding
through chop to appreciate how hydrodynamic these hulls are. As
I appear to have invented this technique for large PVC pipe,
you probably won't see it anywhere else.
Heat-shaping is now complete, and the sanded hull is primed
with white to cover the dark spots so they don't show through
the final paint job. Krylon Fusion works great on PVC. Leaves
no smell, bonds well and doesn't fade in the sun.
A chalk-line grid on the concrete tells me exactly where my
sail should be. Here I transfer the design from my computer
printout to the grid, then cut the sail out.
If you get stuck, meditate on it. Sailmaking can be
challenging. I got a used book on it years ago and just started
making sails for RebelCat 2. So far my sails have worked
A sail-track on the mast is a modern concept. It's a channel
in the mast where the leading edge (luff) of the mainsail
(which has a rope sewn in it) is inserted and follows the
channel to the top of the mast. This holds the sail firmly to
the mast. I invented an alternative sail-track for aluminum
pipe, which obviously doesn't have one. It's very cheap and
works great. You can see it completed in the photo below.
The aluminum mast, showing the forestay (left), the pulley
for the jib halyard above the eye for the stay (top left), and
one of the sidestays (bottom right). The rope creates temporary
sidestays to hold up the mast while the real stays are cut to
Traffic cones for the tail of each pontoon. Not glamorous,
but they actually perform so well that there is no wake at all
behind RebelCat 5. They are glued and riveted to short pipe
rings for attaching to the pontoons or pontoon extensions.
My new way to close the top of traffic cones - wooden knobs
bolted from the inside.
Storage trays under the deck covers hold lots of things one
needs close by, like extra rope, food, water, tools, radio,
first aid, warm clothes, rain gear, etc. They are sewn from
polyester fabric and screwed inside the deck frame under the
covers. The yellow square in the tray is painted cardboard to
The storage trays need some help from a zigzag of nylon cord
to keep them from sagging. The blue webbings are hiking straps.
Slip your feet under them and you can lean out over the water
during strong wind.
Good sail control requires a traveler, and this one is easy
to make from polyester rope and a pulley. A block and becket
form the lower part of the mainsheet pulley arrangement. The
hooks are for a rear cargo net. One hook needs to be screwed
Assembly on a lake shore begins with support spacers which
hold the pontoons at the right width for the cat to be built on
them. Each pontoon is made of two sections, held together by
couplers. This is the 21-foot extended version of RebelCat 5.
By putting the cones on just the aft sections, the cat is
15 feet long. The two 6-foot extensions add about 350 pounds of
The couplers are on, making one long pontoon from two
sections. I think I invented this too. Have you ever seen a
catamaran with pontoons made from two sections? Nor I.
Over the couplers is the deck. In back is the aft spreader
and rudder asembly. In front the bowsprit and fore spreader
connect to the deck.
The mast sections are connected and fitted with stays and
halyards, then the mast is stepped and the boom added. Deck and
seat cushions are strapped on. Centerboard is pinned in place
and rudder controls added. Sheets are threaded through their
Actually a photo from another assembly, this shows me
attaching the jib to the forestay prior to launch. We raised
the jib while in the water.
Fully assembled on Beaver Lake, Arkansas. Assembly by one
person takes about 90 minutes, half that for two people who
know what to do. The cat can be carried either from under the
seats or by the fore and aft spreaders.
Light winds on Grand Lake, Oklahama give us a chance to
swim. Many parts of the cat are suitable for diving from it
into the water. Getting back on board is very easy, and the cat
is so stable that walking around on it and diving from it
cannot tip it over. I don't fish, but I suppose this kind of
stable and spacious cat would be ideal for it. Imagine, a
fishing boat you can't tip over.
As far as sailing, it moves quickly in the slightest
breeze, due to the large sails and little resistance to the
water. It sails very quietly - there is no swirl of turbulent
water behind the cat, no wake at all, due to the hydrodynamic
shape of the cones at the rear.
One part of its sailing character surprised me. It sails
very close to the wind, that is, it points extremely well,
probably due to the large centerboard. Cats are notorious for
having to tack a lot to get anywhere. Not this cat. It sails
like a yacht.
The mainsail has reefpoints about a third of the way up, so
it can be made considerably smaller in minutes. The traveler
allows for adjustments to the sail angle and shape - it is
about 56 inches wide, or most of the width of the cat. Jib
fairlead blocks are also adjustable to five positions each
Cartopping with RebelCat 5 is so easy and aerodynamic. Since
most of the parts are light, one person can handle them. The
largest piece, the deck, goes up one end at a time. Sure beats
pulling a trailer.
What would I change? The forestay could be
attached higher on the mast, creating a larger foretriangle and
hence allowing for a larger jib. I have a new design for both
the rudder and centerboard, although both worked fine. When
they are done, they will appear in RebelCat Updates. That's about
it. RebelCat 5 is a mature and tested design. It sails well,
it's comfortable for long cruises, lots of storage space - I'm
quite pleased with it. If you want to build one, I have
produced a video DVD which
shows and explains the entire construction, step by step. More
about RebelCat 5 here.
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See RebelCat 1