A side scan sonars range scale or operating range is set by the distance that sound can travel out in range and return to the towfish in a given time with an assumed sound velocity of 1500 meters per second (the average speed that sound travels in water). If you select a operating range of 750 meters, the towfish is firing once every seconds. A selected operating range of 100 meters would yield a repetition rate of one sound pulse every .133 seconds.
The swath coverage is twice the operating range since the towfish has a transducers on opposite sides.
A good example of just how much bottom is being imaged is if a towfish were to be towed along the 50 yard line of an American football field, with a operating range of 50 meters, the swath coverage would cover just about all the field and the endzones.
