Using Catarafts with Motors
Cats have some real advantages over conventional zodiac type boats.
With the right frame, a cataraft can be transported around the world. I took a trip to Indonesia in 1996. I booked my passage on the airline as a diver, and took three packages that weighed less than 70 lbs. One 70 lb package was a set of tubes, and one could have been the frame.
Catarafts make excellent fishing platforms. It is possible to hang a mesh live well between the tubes while at rest fishing.
Cats, rigged in the proper way, are great dive platforms. We have a vision of a dive boat made from pontoons. It would have a platform in the front that could be lowered to the water level. This would greatly aid the divers in removal of their gear.
Cats are less expensive to manufacture than conventional sport boats.
It is our experience that conventional sport boats have a high maintenance factor. Because of the torque placed on the transom, it is especially prone to maintenance.
With a set of oars, a cat can be easily taken through the surf with one person. That same person must hold on well because the wave tends to wash through the boat, and they may get washed off of the boat too. Still it is easier to get a cat through the surf than a conventional sport boat.
Catarafts need to have some sort of planing surface if a large load and a large motor are to be used. A wake is produced off of each tube and they converge in the center of the boat. These wakes cause a hump of water to form between the tubes. As the boat accelerates to speed, the hump moves backward, gets bigger, and it could drown the motor. A 6-ft long plywood or diamond plate aluminum deck, attached to the bottom of the back of the frame, is sufficient planing surface. Also the bottom of the frame should be above mid line on the tubes to be effective. Otherwise this planing surface will act as a water scoop. The transom should have adjustability up and down for different loads. However this planing floor compensates for a wide variation in load if planing speeds can be achieved.
For smaller motors that are not expected to plane out the craft, the motor should be placed at different height for different loads. Down River Equipment Co uses a frame system that incorporates an adjustable transom (available through Cabelas) to accomplish this adjustment.
Our experience with Catarafts and Motors are:
On April 15, 1996, I took a boat 36 miles up Lake Powell in 70-mph winds. It was our Expedition Cataraft (15 ft waterline 24 inch diameter tubes X 18 1/2 ft long) with a 9 inch thick inflatable floor, and a 25 hp motor . The waves were coming from every direction. I did not achieve planing speed until the wind died down. The front of the boat acted like a scoop, and every time I hit another wave, the boat would scoop up more of the lake only to drain out. Every 10 seconds it was like getting hit with a bucket of ice water. I had to make the trip because I was picking up my photographer from an Escalante trip, and then doing a photo shoot. On the way back with 5 people and gear the trip went very well. The lake was smooth, and the boat planed very well with 4 pack cats in tow.
In September of 1999, I took this same boat down Cataract Canyon at 8,000 cfs. We ran through the flat water with this boat as the main barge with a 5-hp motor. We had a 14-ft Riken on one side, and a Daddy Cat on the other. At the rapids I switched to the 25 hp motor, and ran solo through the rapids. Later we all tied together, and motored out to Hite with the 25-hp motor.
During the Moab demo day June 21, 1999, We took a 14-ft cat with 19-inch dia. tubes, a 25-hp motor , and a floored frame to Moab Ut. The Colorado was running 20,000 cfs. I was able to successfully up run the Colorado River through whites rapid with this setup. The secret to the floor on this unit was that it folded accordion style in sections for storage. It was tied to the bottom of the frame with no clearance between it and the tubes. The frame was speed rail, and could be disassembled. Have a look under power on a tight turn.
For at least 4 trips to Lake Powell, and 2 trips to Navajo, between the years of 1991 and 1995 we used a 4-hp gasoline motor that was made by the National Pressure Cooker Company in the 1940's. We used this motor on out expedition cat with a heavy gear load to camp in Hall's bay. This motor was very light weight, and easy on gasoline. Although we were not able to plane, we were able to go some serious distance if necessary, and we still carried all of our gear for a multi day trip.
Riley Dunn has used our 28-inch diameter tubes with a 70-hp motor for sea kayak support in the Baja . He now uses this craft for supporting Hobi Cat adventures around the coast of Belize.
There are numerous other instances where our Catarafts are used with motors. We have customers who use them to do hydrology studies, Biologists who use them to study fish and aquatic habitat; they are used in River restoration projects. They have even been used as movie platforms on lakes at 13,000 in the Colorado Rockies. One time I watched a Daddy Cat loaded with gear being motored down the top part of the Desolation Canyon on the Green River, with all the gear, supplies, and 4 people for a 5 day trip. This boat had a 7-hp motor. Although they could not plane the boat with that heavy load and small motor, they made it down river hours ahead of us with out motors.
If you are interested in more information, see our PHOTO GALLERY under CUSTOMIZED CAT TUBES and CATARAFT FRAMES.
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