Search and Rescue - SAR is a commonly used acronym by marine police, sheriffs and fire rescue teams.

Search and Recovery - This version of the acronym is more common with commercial search and salvage.

Side Imaging® (SI) sonar is Humminbird's® registered trademark for the side scan sonar data produced by the Humminbird® sonars.

Side scan sonar is a specific class of sonar which utilizes acoustic backscatter to produce bottom imagery. Side scan sonar was invented by Dr Harold "Doc" Edgerton and refined for commercial use by his student Marty Klein. Some folks incorrectly use Sidescan or Side-Scan.

Is the range directly from the transducer to the bottom or a target. Using a hull mounted system in 100 feet of water the slant range to an object 35 feet off to the side and on the bottom will be greater than 100 feet (106 ft). So the horizontal distance also known as ground range is 35 feet and the slant range is 106 feet. Slant range is also used with radar and is defined as the line of sight between two points which are not at the same level.

Is the distance from the transducer and is measured as a slant range.

In side scan sonars the sonar range setting is the slant range distance from which a single transducer receives data. A sonar set to the 50 meter range will look 50m port and 50m starboard. Total coverage is 2x the range assuming the towfish or vehicle is at the proper elevation above the sea floor.