You need to download/update your charts on the chart installer, it's a free download for your computer. Load all the Sonar charts for the area you want and download them, you can do community edits at the same time. Then select the function in the menu on your chartplotter. I find that I have to change settings regularly. On the Simrad, if you select "All" there is just too much unless you are zoomed right in. I usually back out one setting for regular use and set "All" for prawning or bottom fishing.
I bought the Platinum+ this year, it was a mistake. When you look at the propaganda from Navionics it looks like you will get amazing 3D bottom imaging, not so much. I thought I was doing something wrong so sent screen shots to tech support. The answer was that there was nothing wrong
Looks like crap in my opinion. The Colburne Passage image is another setting and probably the one I will try for the next while. I can also turn off all the Platinum functions and revert to Navionics+