So far, reference has been made to the least tangible part of the equipment: transducer, frequency, power … although what identifies the probe is the screen. Today there are several types of screens, the evolution of television screens is also evident in the probe screens allowing having several modalities: CRT screens (cathode tubes, now in extinction), TFT or the most modern They came to replace them: the LCD screens. The LED screens have made an appearance, and surely new technologies will continue to be generated, so it is better not to waste time defining each type of screen, which makes the following technology obsolete.
From a probe screen, what you need to consider are several basic aspects: size, resolution, and color.
The size is related to the resolution. As in television screens, echo sounders are measured diagonally and in inches. You cannot establish an optimal measure, but consider that the larger the size, the greater the information to be displayed. The dichotomy is usually between a square or a panoramic screen. In principle the two are equally optimal, however, taking into account that the probes are increasingly able to show more information thanks to the combination of equipment, it is best to bet on a panoramic version, which large pogo pins also allows you to divide the screen, a very useful option in multifrequency probes.
The quality of the image deserves special attention: it should be as great as possible, and that depends on the resolution. At present, the resolution is measured by pixels, the higher the number of pixels, the higher the image quality and the details are more accurately displayed. The advisable thing for a good resolution is 640×480 pixels.