Thread: Get to know your dam with DrDepth and a Lowrance HDS

When we started off using old sediment maps, it sure was tough trying to locate all those points, ledges, drop offs, humps, old rivers channels and funnel points. Take this example of Grant’s Bay up in the far NE corner of Inanda Dam. The first and biggest problem was to try establishing where land ended and water began, never mind water level fluctuations. But as you spent more time with it things would start to make sense.


Then we started logging the bottom and using DrDepth created Lowrance Chart Maps, or LCM’s. These have a lot more detail, definition, accuracy and most of all actual depth readings.


DrDepth’s 3D orbit able representation of these bathymetric readings also helped make things a bit easier to understand.


Then came DrDepth BT (Bottom Type). At a click of a button would turn that same 3D orbit able image into a bottom hardness representation. This allowed us to find those harder gravel and rocky areas that our bass seem to love so much and create valuable waypoints for our GPS’s.

Shouldn’t that be enough? No! We are bass fishermen and we need detail, and lots of it. And that is why we now use DrDepth BT + SideScan edition. This now gives us a whole new world of detail perfectly georeferenced on our existing Depth charts.


Looking at the chart when zoomed out seems a little lacking of detail, but when you zoom in, the true gems start to appear. You can now go anywhere in this entire bay at a single slide of the mouse and create waypoints at a click of a button.


These waypoints go straight back to your Lowrance GPS where you can now go drive directly above these points of interest and take real high detail DownScan screenshots of the structure / cover.




I will be running a 2 day course (Sat / Sun) on this technique later this year (after the Boat Show Dive Expo 2010) here in KZN. Please contact me if you are interested.

This is incredible. Does the DRD SI edition use the same source data as before or do you need to record in SI mode?

Did anybody spot the little bass boat from my 'Identifying Structure' thread yesterday in the black & white image? (hint - it's in the NE)

Originally Posted by MarkA

This is incredible. Does the DRD SI edition use the same source data as before or do you need to record in SI mode?

Good question Mark.
You will use your original .slg recording for depth and BT data. Your SideScan mosaics simply become an overlay that you can control contrast, brightness, colour etc.

If you have no data for lets say a new area, you will merely select 'All Channels' when starting your log on your Lowrance HDS. These channels (200kHz-depth & BT and 800kHz SideScan) will be imported to DrDepth seperately. To view the different modes you will either click on DTH, BT or SS.

You can also import this data live to your laptop as well now through the Ethernet port of your LSS-1. Or send it from your LSS-1 to a wireless LAN hub installed in your boat and receive the data to your laptop wireless.

John,

What were your DrDepth settings for the Side Scan map: sensitivity, contrast, image resolution, drawing mode?
I don't get it as detailed as your map is showing.

Did you make the map by live-mapping on the water, trying not to overlay tracks? At what distance between the tracks ? Is there a way to determine the ideal distance between the tracks without live-mapping?

DrDepth seems to be the only way for the moment to mark waypoints quickly on the side scan loggings:
Lowrance Sonar Viewer 2.1.0 doesn't let you mark waypoints.
There is no HDS emulator available yet.
On the unit itself, it is impossible to scroll in the SL2-file, so every minute of recording has to be watched ...

Originally Posted by DannyGeysen

John,

What were your DrDepth settings for the Side Scan map: sensitivity, contrast, image resolution, drawing mode?
I don't get it as detailed as your map is showing.



Did you make the map by live-mapping on the water, trying not to overlay tracks? At what distance between the tracks ? Is there a way to determine the ideal distance between the tracks without live-mapping?

This was done using a 150ft SI range with your chart map range ring set to the same (150ft), the Minn Kota i-Pilot did make a big difference maintaining course. But in future all my routes will be pre-planned and saved as a route on my HDS10. (far more accurate)

DrDepth seems to be the only way for the moment to mark waypoints quickly on the side scan loggings: Unfortunately it is, but it works a charm and is so fast, especially if you are using a little laptop on board.

Lowrance Sonar Viewer 2.1.0 doesn't let you mark waypoints.
There is no HDS emulator available yet.
On the unit itself, it is impossible to scroll in the SL2-file, so every minute of recording has to be watched ...

Things are improving so quickly now with Lowrance, I'm sure our solutions are just around the corner.

Thank you very much John,, I will give it a try...

Danny Geysen