Most of N2K displays I'm testing let a user choose the source of a particular data type if there is more than one on the backbone, but they don't let you show two of the same type, except for items that are commonly multiple like engines and tanks. Some Lowrance MFDs are an exception, but I'm not sure that feature migrated to the HDS series (I'll check), and I recall that it did not apply to depth for some reason. So you can often get double depth read-outs by setting different displays to different sources, but maybe only Maretron supports the screen above. The trick was to change the "Instance" of one transducer from the default "0" so I could then select different instances of Depth when setting up the screen. Not every manufacturer gives you the ability to change Instance, though Maretron is great about it, and you almost invariably need a same manufacturer display or software to make the change. Instances is one of those areas of N2K that most users will never need to know about, and I find confusing, but it seems to have powerful possibilities.