This is a short tutorial that outlines a simple way to export maps with hardness overlays for Navico units.

In this example, we create and export a simple map that targets the widest possible range of units, producing a map card that is fully compatible with everything from the LMS/LMX range through to the latest HDS touch units.

This is the map we are going to export, shown in the ReefMaster 3D view – a lake from one of our beta testers (thanks Peter!):


This is the map shown in the contour view of ReefMaster:


Note the hardness areas in the grey colours, overlaying the depth. The hardness display has been configured by adjusting the “display lower” slider, so that it is just showing the harder areas in the lake. Limiting the displayed and exported hardness areas is a nice way to keep your finished map uncluttered – in practice, you are likely only going to be interested in certain types of bottom-composition, and exporting just these areas makes the bottom-composition overlay far easier to read when on the water.

We could export this map directly from the contour view, but for complete control over the look of the finished map we can create a User Map, which lets us edit just about any detail of the map; depth or hardness area colours, individual contour colours and widths, add extra features etc.

To create a new user map with all of the components shown in the contour view, select the option Add to map.../All components…/New User Map. At this point, the selected palette for depth and hardness does not matter – we are going to set all the colours again by hand in the user map.

User Map:


We are going to keep this map simple, un-cluttered and compatible with as many units as possible, and to that we need to use colours from the first 21 colours in the Navico colour list, and avoid using transparency. (Note: you can enforce these restrictions in a User Map by setting the Navico Compatibility parameter to “Common” in the Global Settings – or else, just be aware of these restrictions and choose your colours accordingly).

For depths, we are going to use two shades of blue for shallower areas, with white for deeper water (colour ID’s 9, 16 and 15). Colours for a group of components can be changed together by multi-selecting the components in the list at the right of the screen, right-clicking and setting the required values in the menu. Depth areas can be sorted by depth, which makes setting a colour for a particular depth-range very easy.

For hardness we are limited somewhat by the colour range available in the “Common” scheme. Two shades of grey – 7 and 8 – are available, so we have coloured the lower half of the hardness range in the lighter shade, and the rest in the darker shade.

Now the map is styled, we can export it; right-click in the map and select “Export to GPS”. This map is vector only, with no transparency, so the “Export Background Raster” option should be unchecked. Once the map export process is complete, you will be left with two files; at5.xml and Large.at5. If you did not export directly to a memory card, then you should copy both of these files to the root of a memory card and insert that card into your GPS device.

Map on a Lowrance LMS 520C:


This is how the map looks on the Lowrance LMS 520C emulator. If you don’t have a Lowrance emulator installed, it is well worth getting hold of one from the Navico website for testing maps.

Zoomed in:


Many Lowrance units, including the LMS and HDS series, have a function to show or hide components of different types in vector maps. This is an incredibly handy feature that allows the visibility of the bottom composition layer to be toggled whilst on the water. ReefMaster bottom composition areas are stored in the category Bottom Composition/Misc - use the Chart/Categories menu option to show or hide this layer.



Same map, no hardness overlay - this change can be made whilst on the water:


The same map files, shown on an Elite 5:

What is actually the best hardness setting type for fishing purposes, E2 or Composite?

My experience says E2 (probably E1 if you have enough of that data). Be aware if mixing loggings from different sources/hardware (even firmware versions). Use scale and offset to harmonize hardness values.

Scale and offset are settings I don't understand much of yet.

Those are used when importing sl*-files. If you only have data from one single unit/transducer you don't have to worry about it. But if mixing data from several sources you need to understand each source will have its own "scale" when it comes to producing hardness numbers. If you don't take that in consideration you will end up with a result not showing what you want. For example hardness value 60 might be extremely hard if it is produced by unit A but only moderately hard if produced by unit B.

Scale and offset are the tools RM provides to harmonize different sources hardness numbers to the "base scale" you have decided to work with.

Using the histogram feature for the different sources you will be able to establish the scale/offset to use. Making good hardness-maps using several sources means a lot of work, but with RM it is possible. In the DrDepth-days it was so difficult I only used a single source.

Is there a plan to explain this steps with a short video and used functions explanation for the noobs out here ?

We do have plans to produce a series of short video tutorials - this would be a good topic!

How do this tutorial apply to RM 2?

I'm unable to find Display Lower settings anywhere.