Here's an image from my HDS that shows my settings. They are going to be very similar on your unit Eenakok.
- hds_web.jpg (116.26 KiB) Viewed 5095 times
Hit "Menu" twice and you should see "Sonar" with an arrow next to it. Scroll down, click on that, and most of the settings will appear. You will most likely need to have your sensitivity set to between 90 and 95 percent. The best thing to do is run the sensitivity all the way up until the screen is almost entirely cluttered and then back it down from there until you get a good image. Play with your Colorline to further improve the image and with the Noise Rejection setting if there are quite a few other boats around. I can't remember if there are settings for Trolling Speed or Freshwater/Saltwater on that unit or not. If it has those options run it on Freshwater all the time...even in Puget Sound.
Hope that helps. Feel free to axe if you have more questions