Jun 28 2011

Hydro Survey: The Cataraft

Cataraft on Rio Grande River

In a previous post, I discussed the use of jet boats for hydro surveys on shallow western streams. A jet boat is fantastic in how it can get almost anywhere, even through just 4 inches of water. However, you still need a boat launch for a jet boat (or prop boat). What about a survey site without a launch? What about a smaller mountain channel? This is where a cataraft comes in handy. It’s essentially a frame with two pontoons attached with straps that is typically used for rafting. In the picture below you can see our GPS and depth sounder set up. We’ve since upgraded from the Innerspace (now a part of Odom) 455 to the Sonarmite, but you get the picture.

Cataraft on the Truckee River

The GPS antennae and transducer are attached to the PVC pipe at the front of the boat. It has the ability to swivel it up to avoid obstacles and rocky sections of the stream. The driver obviously sits in the back chair while the “operator” sits in the middle monitoring and controlling the hydro survey. The motor is a small Yamaha prop. In a typical hydro survey you like to move from downstream to upstream. It’s easier to deal with the current and to accurately drive to get the sections you need. With a cataraft, you need to survey upstream to downstream. It’s pretty maneuverable but it’s not exactly the speediest boat on the planet, especially in a small, steeper stream. You can portage around obstacles with a cataraft but it’s difficult. Between the batteries powering the equipment, the laptop, GPS system, and the depth sounder, you have to unload the equipment to do so. It’s heavy and takes some time to set up and take down.

Pueblo Dam Survey using Robotic Total Station

But the beauty of a cataraft is having the ability to hydro survey anywhere: a small mountain stream, at the base of a dam outlet (see above at the outlet of Pueblo Dam), or in a pond or small lake. These things can take a beating as well (just not old spiked railroad ties in the river – that’s another story for crew chief!). At first, we questioned if we’d get the use out of this boat to justify the purchase but we’ve been proven wrong. Between a cataraft and a robotic total station, you start to eliminate inaccessibility.

1 comment

1 ping

  1. Luiggi

    Good Moorning

    It is a pleassure to participate in this communitiy.

    I would like to know if the multibeam and accessories are possible to install in a cataraft, at this momment i am searching for a boat with low price and the capabilities for hydrographic surveys with multibeam.

    Thanks in advance.

    Best Regards

    Luiggi Cardenas

  1. » Hydro Survey: The Setup and Software Hydraulically Inclined

    […] talked about jet boats and the cataraft for hydro survey. Now let’s dig into the set up and the software. Above is the typical setup with […]

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