There are many navigational tools and means available for boaters. The marine radar is arguably one of the more difficult ones, not only because those radars tend to be more costly than their cousins, but also because operating and reading them aren't quite a breeze for the untrained.
Let's have a closer look at those devices.
On a fundamental level, marine radars function similarly to echo sounders, which is, transmitting an energy pulse and then measuring the time it took for the pulse to bounce back. The main difference between the two lies in the means; while echo sounders utilize ultrasonic sound, marine radars do their magic using microwaves. The main device measures the time it took for the waves to return, and calculates distances based on that.
Reading and operating a marine radar requires experience and skill. The content on the screen doesn't look familiar and one will need training to get the idea of what the display is trying to tell you. On top of that, the use of marine radars can be somewhat of a hassle. Merely turning them on requires some time for warm-up; the device also needs the occasional setting-up, adjusting, and tuning according to the conditions of the location you're boating in.
There is an alternative choice free of many of the difficulties inherent for the traditional magnetron radar. The broadband boat radar, introduced to the scene fairly recently, is magnetron-free, doesn't need time to warm up, uses a fraction the amount of peak power than it's older cousin, and does a far better job in general with way more precision. You'll also find yourself spending less time tuning and tweaking than you will with a magnetron radar.
What to Look for
Here's a quick run-down of the main qualities and features you should be focusing on when shopping for a marine radar.
Peak Power Output. Powerful signals translate into wider range and sharper focus. The more peak power output the device offers, the longer the range of detection and the more accurately it will be able to "catch" small targets.
Horizontal Beam Width. With it's main implication is the quality of the picture displayed on the screen, a wider beam will typically display a less defined picture than a narrower one. Keep on mind, though, that in rough water, or aboard smaller boats, there's a disadvantage to narrow horizontal beam, since the signal tends to drop targets as the boat rocks and pitches, whereas a wider beam will tolerate greater angles of list and trim.
Antenna Size. A larger antenna will provide you with a better picture. Marine radars use microwave frequencies, and the more receptive the unit -- i.e. the larger the antenna -- the better a picture the device will be producing.
Analog and Digital. While an analog radar will be cheaper, a digital device will provide much better quality. Digital signal processing has significantly enhanced picture detail while reducing interference. Digital, high definition, UltraHD and DSP, or digital signal processing, all indicate superior radar characteristics.
Screen Size. Last but not least, is the pixel point. The larger the screen, the more pixels it tends to have. More pixels translates into better quality images.