The Mark-4 HDI has a 30% larger screen than the original Mark-4 series. At just a little above 4 inches, this guy is roughly the size of an iPhone screen – which should be comfortable viewing when mounted on the dash or near it – it’s not a behemoth like the HDS, which you can see from across your boat, but it should do fine for weekend fishing trips this summer!
Mark-4 HDI 50/200 – 455/800 Fish Finder, the easy-to-use 4.3″ fish finder with Hybrid Dual Imaging, combines Broadband Sounder with DownScan Imaging technology, a super-bright, LED-backlit grayscale display, built-in GPS antenna and high-definition mapping.
Key Features:Lowrance-exclusive, brilliant, high-resolution, 4.3″ , LED-backlit grayscale display Exclusive Hybrid Dual Imaging (HDI) – Broadband Sounder plus DownScan Imaging — the power of two award-winning technologies combined to provide the best possible view beneath your boat highly accurate, built-in GPS antenna plus a detailed U.S. map featuring more than 3,000 lakes and rivers and coastal contours to 1,000’Optional chart upgrades include Lake Insight and NauticInsight PRO and HD, Navionics Gold and HotMaps Premium,Fishing Hotspots PRO.
Along with viewing things in split-screen like you see in the picture above, you can overlay DownScan SONAR and regular SONAR onto one large display. This way you can get the best of both, since DownScan is better equipped to find structure and regular SONAR is better equipped to find individual fish.