The world of fish-finders has been turned upside-down in the past few years, with side scanning sonar, forward looking “flashlight beam” sonar, “CHIRP” multi-frequency fishfinders, and high-resolution down-looking imagers. Now Raymarine is rocking the boat yet again with the CP200. This new system, which Raymarine has dubbed “SideView,” ties two of these technologies together by incorporating CHIRP with side scanning.

raymarine cp200

The all new Raymarine CP200: why not add CHIRP multi-frequencies to side scanning sonar?

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Side scan abilities give you exactly what it sounds like—the ability to “look” sideways off to either side of the boat, with a fan-shaped sonar beam. Most systems incorporate very high frequencies (455/800 kHz beams are common, as opposed to the 50/200 kHz beams utilized by traditional sonar) to provide exceptional detail. The down-side to high frequency, however, is reduced range. The easiest way to understand why is the pebble-and-rock analogy, which we used in our sonar technology comparison Sonar Smack-Down: Traditional Fishfinder Vs. Down-Looking Scanner-Imager Vs. CHIRP.

Think of sonar waves like ripples on the surface of a pond, which are created when you throw pebbles and rocks into the water. When you throw a pebble, it creates a series of small, tight, fast-moving waves, which are easily reflected back by anything on the water’s surface. These are like your high-frequency sonar waves. But when you throw in a big rock, it creates larger, slower, more widely-spaced waves, which roll right over small items floating on the water’s surface without being reflected. These are like your low-frequency waves.

While the high frequency waves are reflected more easily—providing that higher detail level—they peter out quickly and don't travel nearly as far as the larger low-frequency waves. That’s why most side scanning finders and high-resolution imagers have extremely limited range.

Now, let’s toss CHIRP into the mix. This sonar technology, which has also been called “Spread Spectrum,” “Clear Pulse,” and a number of other names, is simply the use of multi-frequency pings in a rapid-fire blast, instead of the usual single-frequency ping. Rather than sending out its waves at 50 kHz, 200 kHz, 455 kHz, or any other single frequency, it blasts out the series of waves in different increments. Exactly what the increments and the total range of frequencies it covers are varied, depending on the manufacturer and the model. But the idea is to take advantage of multiple frequencies at the same time to get both the high definition of high frequency ranges, and the depth penetration and range of low frequency ranges.

cp200

In this CP200 screen shot, you can see pilings in the water column, off to the sides of the boat. The long black lines are the "shadow" they cast from the sonar waves.



Net result? The CP200 boasts a claimed range of 600’ to either side of the boat. While this might not sound like much, remember that most side scan sonar claim a maximum range of around 250’—less than half of the CP200.

But, is its useable range going to match up to the claims? Only time and on-the-water experience in varied conditions will tell, so it’s too soon to draw any solid conclusions just yet. That said, we need to note that the useable range of previously existing side scanners is significantly less than the claimed max range. I’ve used side scanners of various types for several years now, and in practice, at between half and two thirds of a unit’s claimed maximum range its usefulness often fades.

The most unusual part of this system in particular is probably its transducer, which had to be custom engineered to add CHIRP into the side scanning mix. It has independently adjustable port and starboard arrays, as opposed to incorporating both side’s arrays in a single body. Raymarine says this allows you to adjust each for better shallow, mid, or deep depth ranges.

The CP200 networks with a wide range of Raymarine MFDs, including any LightHouse II (version 10 or later) a, c, e, and gS series units. It can also be viewed simultaneously with other Raymarine sonar, though you should remember that as you start splitting the screen between multiple fishfinders and chartplotter views, screen size becomes imperative. Picking out details, for example, on a nine-inch screen that’s showing three or more views, gets quite difficult.

The little box of Raymarine magic is 8.9” long, 6.4” wide, 2.8” deep, and weighs 1.3 pounds. It’s waterproofed to IPX6 and IPX7 standards, and runs on 12/24V dc. Availability begins in August of this year, and MSRP is $609.99.

For more information, visit Raymarine.

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