Looked like good holding bottom here, and the depth sounder showed they were entering the hundred fathom line.

The fathometer, or depth sounder, was developed commercially during the 1920s.

The wreck is the largest feature to appear on a depth sounder in the area, standing about 3 metres off the harbour floor.

Using the depth sounder, a submarine could locate the peak of the seamount, which was a known position.

Wilbanks glanced up at his depth sounder, which hung from the roof on one side of the helm.

The fisherman who relies on a depth sounder to locate his catch may find the job easier with a new sonar device.

The LDD-1800 was one of the first digital depth sounders to be controlled by a tiny computer built inside.

When the target began to raise on the depth sounder, he shouted, "Now!"

Chao checked the reading on the depth sounder.

According to the depth sounder, the bottom's beginning to drop off.