Lowrance LCX-20c Fishfinding Sonar & Mapping GPS

This new Lowrance product is marketed as a recording sonar (fish-finder), but is equally at home as a chart plotter. It can be supplied as a stand alone item or complete with sonar transducer and GPS receiver and comes complete with a mounting bracket.

Lowrance LCX-20c Fishfinder

The LCX-20c has a bright sunlight-viewable screen 5.25 cm diagonal (6 inches) with a 240V x 320H resolution (1/4 VGA) and 256 colours. The case is waterproof and there is a waterproof housing for 2 MMC or SD memory cards up to 1 GB each, on which routes and charts can be stored.

A number of sonar transducers are available, but the most suitable for installation on a sailing boat will be either the transom transducer epoxied onto the inside of the hull, where it 'shoots through' the fibreglass hull, or preferably, a 'through hull' transducer. Both are available as single or dual-frequency units.

The LCX-20 can be supplied with Lowrance's own GPS receiver. This has WAAS (wide area augmentation system) which gives enhanced accuracy from differential GPS signals transmitted by satellite. The European equivalent EGNOS, is compatible with WAAS. If you already have a GPS, the LCX-20 can be connected to this to derive its position.

There was no loose quick start guide supplied, so I checked the wiring diagram and connected the LCX-20 to a 12 volt supply and did what most of us do in any case - switched the unit on! It soon became apparent that the LCX-20 is very user friendly. Press Menu once and you get a first level menu, press it a second time and you get the second level menu for setting up the system. You navigate the menus by the use of the enter, exit and cursor keys. All very logical and the menus are in the style of MS Windows. They keyboard is backlit for use at night, there are three levels of backlighting and total power consumption is a miserly 700 ma.

The PAGE key brings up a menu from which you can choose one of four different pages: Status (GPS), Navigation (How to get from point to point), Map (A display of the chart) and Sonar (The fishfinder display).

Pressing the MENU key brings up the first level menu which will differ according to which of the three pages are displayed; Navigation, Map, and Sonar.

Pressing the menu twice leads to this screen

Highlighting an option will bring up a secondary window explaining what that option does.

Pressing the MENU key a second time displays the second level menu, common to any window:

The screen can display Navigation data, Map or Sounder or may be split to show any two of the above.

SOUNDER OPERATION

For best operation of the sounder careful set up is required. I was given the opportunity of going on a fishing trip with Bertrand Picarda, Lowrance's European Manager and a very keen angler. We navigated to a wreck site, but the fish finder saw no wreck on the bottom. After searching round a bit we found the wreck showing up very clearly on the fish-finder about 50m from its charted position. Not only was the wreck clearly represented on the screen, but it was very easy to see that that was where the fish were. Highlighting an option will bring up a secondary window explaining what that option does.

The screen adequately showed the depth of the fish

Bertrand showed me how to adjust the setting to best effect and he was able to discern what type of fish were on the bottom and proved it by catching what he said was there. You could watch the screen to see that you were 'jigging' exactly at the depth the fish were swimming.

Sliders to adjust the various sonar settings, such as sensitivity, can be permanently displayed on the sonar screen if desired, the settings being adjusted with the cursor control.

Lowrance has an excellent tutorial on their web site here so that with practise, you can do the same.

CHARTPLOTTER OPERATION

Daily graphs can be accessed from the tidal display

Lowrance uses Navionics cartography for its marine charts and these are supplied on MMC memory cards. The amount of chart detail displayed can be altered using the menu and the speed that the chart was redrawn was fast.

Tidal flow and tidal height are shown at selected points. By pressing the WPT key whilst tidal display is shown, daily graphs are displayed.

Routes were easy to construct by selecting Route Planning from the map menu and then locating the position of the waypoint using the cursor and then pressing the WPT key. Waypoints can be moved or deleted from the edit route menu and distance and bearing between waypoints can be displayed. 100 routes of up to 100 waypoints each may be stored.

You can navigate in MAP view or you can select NAVIGATION and use the compass which also shows cross track error.The position icon can have a predicted track vector added, the length of which can be set at different lengths or times. There's even more that you can do so have a good look at the excellent 194 page operating instruction book.

This is an excellent piece of kit, worthy of a place on your short list if you are looking for a fishfinder/chartplotter.

	Pat Manley

Pat is an Associate Fellow of the Royal Institute of Navigation and has been sailing dinghies since 1959 and cruising yachts since 1984. He is a Yachtmaster Instructor (sail) and Yachtmaster (power) is the principal of 1 to 1 Navigation and sails a Westerly Oceanquest 35. A member of the Yachting Journalists Association, he is a regular contributor to Practical Boat Owner Magazine, he also writes for Fernhurst Books who have published his Diesel Companion, Electrics Companion and Radar Companion. Just published is his new hardback book, Small Boat Maintenance. www.1to1navigation.co.uk