Comparison Humminbird Helix 5 DI GPS vs Humminbird Helix 5 DI

The type defines the general purpose of the device.

— Echo sounder. Echo sounders are devices designed to study water bodies using sonar. The principle of operation of an echo sounder is similar to that of a radar, but it does not use radio waves, but ultrasound. The initial purpose of such devices is the creation of topographic maps of the bottom of a reservoir, the determination of its topography and depth in various places. However, in addition to this, the echo sounder can be used to detect fish, and with good quality of the device and correctly set settings, you can even determine the approximate size of potential prey.

— Chartplotter. A chartplotter can be described as a dedicated GPS navigator designed for marine use and equipped with related additional features. Such functions include, at a minimum, working with sailing directions (detailed maps of water bodies, indicating depths, currents, etc.); in addition, support for meteorological services, additional equipment such as radars or specific navigation sensors, etc. can be provided. Note that the GPS receiver can be either built-in or external; see Chartplotter Specifications for details.

— Sonar chart plotter. Models that combine the capabilities of both types described above in one device. Such devices are the most versatile, however, and cost accordingly.

— Sonar fl...asher. A specific type of echo sounder, designed specifically for use in one place, without movement. Initially, such devices were generally developed for fishing from an ice hole in winter — although this is not limited to such fishing — flashers are also used in summer, including in open water when fishing from a boat. Such devices are by definition capable of displaying fish in real time (see "Functions"), however, instead of a traditional screen, a circular indicator is used, thanks to which the user can determine the direction of the detected object. And the features of this object (more precisely, the signal reflected from it) can be determined by the colour of the mark on the indicator: for example, a red mark corresponds to a strong signal, yellow to an average signal, green to a weak one. Another advantage of a flasher over a traditional fish finder is its high sensitivity, which allows you to follow even small baits. Thanks to all this, such devices are quite popular among anglers, however, they are not cheap.

Echosounder support for special bottom scanning technologies.

"Viewing" the space under the bottom of the boat is a classic sonar mode and is supported by all models by definition. However, in normal mode, the sound beam propagates in the form of a cone, and the area of the bottom that falls under the beam has the shape of a circle. This degrades the accuracy and does not allow you to achieve a detailed image. Thus, many echo sounder manufacturers have developed special technologies to improve the performance of the instrument; Lowrance has DSI, Hummingbird has DI, Garmin has DownVü. The nuances of these technologies may differ, but the basic principle of operation is the same: the echo sounder beam narrows and goes not in a cone, but in a strip. Due to this, the resolution of the device is significantly increased; at shallow depths, such an echo sounder can “draw” even individual stalks of algae, making it possible to distinguish underwater thickets from schools of fish. Some models combine a narrow beam with a classic cone to further expand detection capabilities. However, such devices are expensive.

The presence of a native GPS satellite navigation module in a device with a chartplotter function (see “Type”). This module is responsible for determining the current geographic coordinates of the device and is thus a key element required for effective work with maps. At the same time, there are chartplotters that do not have this function — they are designed to connect an external GPS receiver.

The presence in the design of the device slot for working with removable memory cards. Some models may have more than one of these slots.

Memory cards are very popular in modern portable electronics due to their lightness, compactness and relatively low cost. In chartplotters, such media can be used both to expand the device's own built-in memory, and to exchange data with other equipment — for example, rewriting tracks on a laptop or downloading updated navigation maps from it (see below). However, it is worth considering that there are many varieties of memory cards, in most cases incompatible with each other. On the other hand, chartplotters usually use a common standard media, most commonly SD or microSD.

The presence of a base card in the delivery set of the device.

The base map is a pre-installed map that is stored in the device's memory. Thus, a chartplotter in this configuration can (theoretically) be used out of the box without installing additional software. In fact, although basemaps may vary by model, manufacturer, and region, they are often small scale, displaying only the most general (often outdated) information, and unsuitable for professional use. Therefore, this function, usually, does not eliminate the need to install additional detailed maps (see below).

Ability to load new navigation charts into the chartplotter.

This possibility is extremely important in the light of two points. First, the base map (see above) rarely provides the level of detail needed to be used effectively — you have to download more detailed maps of individual areas. Secondly, it is very desirable to update even already loaded maps from time to time, since hydrographic information (depths, currents, shoals, fairway location, etc.) is constantly changing.

The maximum number of individual waypoints that can be stored in the chartplotter's memory.

Waypoints can be used as a base for routing, as reference marks on a map, such a point can be set as an immediate destination, etc.; specific use cases depend on the instrument model. But anyway, the more waypoints you can simultaneously enter into the chartplotter's memory, the more convenient it is to work with them and the less often you have to clean this memory to make new marks.

The maximum number of tracks that can be stored in the chartplotter's memory at one time.

If you have to regularly travel on fixed routes, it is much more convenient to memorize these routes once and then select the desired option than to reprogram the navigator each time. Modern devices can store several tens or even hundreds of routes; the larger this number, the less often you have to free up memory for new routes.

The maximum number of waypoints that can be set in one recorded route on the chartplotter.

In modern devices, this number can reach several tens of thousands. The abundance of points is important when laying complex routes, with many turns and curves that require maximum accuracy. Do not confuse this number with the number of individual waypoints (see "Number of waypoints"): in this case, only points included in a particular route and not used separately (there may be many times more) are meant.