That’s a strange, but very impressive fishfinder scroll on the NavNet 3D MFD8 above, and bigger here. You see, Furuno claims that its new SC-30 satellite compass is so sensitive to a vessel’s altitude, which really only changes as it heaves up and down in seas, that NN3D can use that input to remove heave error from its fishfinder screen. I was pretty skeptical about that claim until the end of my NN3D cruise off Cape Cod, when Iker Bryzo uninstalled the SC-30 and showed us how simply pumping it up and down a couple of feet registered immediately on the screen above. If it can respond to small, quick movements like that, it can surely detect swells and likely also compensate for pitch and roll, and thus stabilize side scanning sonar. Amazing! The SC-30 also accounted for the lightening quick and accurate heading/overlay data I saw that day. In fact I asked that it be removed from the system for a while so we could see how NN3D Time Zero did with just the output of a Furuno PG500R compass; the “like real” boat heading line and overlay still worked well, but with a dite more hesitation. 
    Unfortunately, the SC-30 apparently still isn’t available from FurunoUSA (though it’s listed on the company’s home site, and there’s at least one happy user in the U.K.). Meanwhile, my take on that May trip, the August PMY electronics column, just went online along with write-ups of the 4’ UHD radar and the SC-30. The screen above, incidently, shows again how a zoomed-in NN3D raster chart can look crude, especially on a MFD8, but you can also argue that the more precise looking vector equivalent isn’t any more accurate (because it was traced off this) and/or that Furuno has done a great job of abetting these charts with “fused” photo maps.