The data processing capability of the 104C is evident from the speed with which it redraws the screen when it's operating as a chart plotter. The internal memory records sonar and chart plotter data and stores up to 1,000 waypoints; 1,000 event marker icons (choice of 42 icons); 100 routes, each containing up to 100 waypoints; and 10 trail records, each comprised of up to 9,999 points. Depending on the chart in use, a total of 37 levels of image zoom are available, ranging from 0.05 to 4,000 miles. The built-in map detail includes 60,000 nav-aids plus 10,000 other items of interest in coastal and the Great Lakes waters, plus extensive information about topographical details, highways, roads, streets, etc. Sonar data and position information can be saved to a MultiMedia Card (MMC) or Secure Digital Card (SDC) for permanent storage (20 minutes of data will fit on a 11.7 MB card). Data recorded on these cards can be used with the downloadable Lowrance Sonar Simulator (PC-based) software for trip analysis off the boat.