Sonar Viewer

The ReefMaster Sonar Viewer is a Windows PC application that combines a multi-channel sonar viewer with the display of side-scan sonar over a world base map. The sonar viewer works with sonar logs from Lowrance and Humminbird units, and lets you view any combination of your available sonar channels with smooth playback at speeds of up to 30x. Waypoints can be created and edited in the sonar or map views, and loaded and saved in a variety of file formats.

Note: Lowrance users should look at our Waypoint Manager/Sonar Viewer for Lowrance application, which includes Lowrance-targeted waypoint, trail and route management features as well as a multi-channel sonar viewer.

Why use a sonar viewer application on your PC?

  • More Detail
    Sonar logs are typically recorded at a much higher resolution than can be displayed on even the largest units, whose screens are still small when compared to a typical PC. The ReefMaster Sonar Viewer will show your sonar logs with a level of detail that you just can’t see on the water.
  • Easier to use
    Modern sonar units work great, but nothing beats using a computer to quickly control sonar playback, pan and zoom and for creating and editing waypoints over interesting features that you may have missed whilst on the water.
  • More features
    The ReefMaster Sonar Viewer can do more than your unit, including displaying sidescan sonar data in the map view, measuring distances, estimating object heights from shadows and saving image snapshots.
  • More Convenient
    Reviewing your sonar logs on a computer is a lot less hassle than going out to sit in the boat, or rigging up your fishfinder inside. Simply take the memory card out of your unit and pop it into your PC or laptop. You can store as many sonar logs as you like on your PC, and easily switch between them.


  • Supports Humminbird and Lowrance sonar log files.
  • Multi-channel sonar viewer can display any combination of available sonar channels.
  • Map view displays in-situ sidescan sonar over world base map.
  • Brightness, contrast, automatic gain correction and noise reduction.
  • Range of sidescan and 2D sonar colour palettes.
  • Display, create and edit waypoints, with loading and saving of waypoints to a variety of file formats.
  • Measure distance in the map or any sonar channel view and estimate object height or depth in the sidescan channel view.
  • Save or copy image snapshots from map or sonar views.
  • Metric or US units.

Easy to use and highly controllable

The ReefMaster Sonar Viewer is extremely simple to use and easy to control. Zoom in or out of the map and sonar views using the mouse wheel, "zoom-box" or pinch-to-zoom on touch-screen devices. The map or sonar positions can be moved by dragging with the mouse, even whilst the sonar is playing. Image controls such as brightness and contrast are available for each individual view panel via pop-up controls

Flexible Layout

The relative sizes of the map and sonar viewer displays can be easily adjusted by dragging any of the dividing bars, and the individual displays can be toggled on or off. View both of the displays at once, sonar only or map only.

Range of Colour Palettes for 2D and Sidescan Sonar

Work in the palette you are most comfortable with by choosing from a wide range of palettes suitable for 2D and sidescan sonar.

Measure distance and estimate object height

The ReefMaster Sonar Viewer features simple, "click and drag" distance measuring in the map and any of the sonar channel displays. In addition, the height (or depth) of objects in the sidescan sonar channel can be estimated by measuring the length of shadow.