Lowrance HDS Gen2 Review 2011 On August 17, 2013

Lowrance HDS Gen2 Review Part 1

Lowrance announced the new HDS 2nd generation December 2011. This has been a hot topic on internet marine electronics forums with many questions about how it compares to the 1st generation HDS. For this discussion I will use Gen1 and Gen2 for the 2 generations of HDS models.


I have not used the Gen2 on the water (too cold in Minnesota for Doc to be on the Mississippi river..). The images I created are from my old .sl2 files converted to maps and using the simulator to replay the files.

The major differences in the Gen2 are the faster processor, increased internal memory and StructureMap. The transducers, Ethernet, NMEA 2000 and power cable are the same as the first HDS models (Gen1). The menu and features are almost identical.

The faster processor will allow faster map re-draws and faster response to button selections.

The increased internal memory allows longer TrackBack viewing. This is very important to me since I make almost all my waypoints with this feature.

The StructureMap feature is by far the most important difference. 

StructureMap allows you to view the side scan as a mosaic on the chart window. I think of StructureMap as a method to create a personal side scan map of structure on the water so I can use it for fishing. 

This image shows a boulder point, the cursor plus sign is over the same spot on the map and DownScan. This is a spot on the spot that anglers miss and now it is obvious why it is good. The background map is one of my depth maps created with software a similar map can be created with Lowrance Insight Genesis.

There are 3 methods for displaying the side scan mosaic (StructureMap).

  1. Live (temporary )
  2. Record a file (log sonar data) and create a map as a permanent copy
  3. Create a map from a previous saved recording

Recorded files of StructureScan are named .sl2 when saved. The HDS converts them to .smf files which are the mosaic side scan image files that I have used in the above screenshots.

Live StructureMap

The Gen2 has the ability to display the side scan as a mosaic. Think of this as the trail with the sidescan image overlaid on the trail so it follows the trail path and is actually showing the side scan on the chart display.
Permanent StructureMap

If you record a chart (log sonar data), this .sl2 file can be converted into a permanent map to be used in the future or shared with a friend (be careful sharing fishing spots or they get crowded).

The StructureMap is used as an overlay and you can adjust the transparency to view the chart contour lines on the map. This will work with any map displayed in the HDS. You can use the HDS built-in maps, Navionics or DrDepth created maps.

Waypoints will also be overlaid on the StructureMap.

As I learn more I will do more reviews and thanks to Lowrance for adding a tool to help me catch more fish. Dynamite may be better but the StructureMap is legal…


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