The underwater noise was measured by piezo-electric hydrophones submerged in the water at three different depths. The signals were led through connection cables to preamplifiers, and recorded simultaneously by a four channel tape recorder, and analysed by high resolution signal analyzer. The measurements were carried out at the fjord Skossvassen in archipelago off Bergen and at the cost of Norway in the North Sea. The results of the measurements and the analysis showed that the underwater noise consists of a steady broad band noise superposed by intermittent pulse of various strength. The noise levels measured in fjord Skossvassen indicated that they were generally higher at the shallow (10m) hydrophone than at the deeper hydrophone (25m, 50m). This tendency was not very distinct, however, the noise sources are close to the surface. The underwater noise spectrums measured in the open sea of Norway showed almost similar situation in all layers. This tendency showed that the noise sources are not close to the surface but they are far away from the measuring positions.