The single bubble marine seismic source is operated by centering the output signal of an air gun array on the first bubble pulse and has been recently tested in several seismic experiments with deep crustal targets. The results of these experiments show that this source produces a low frequency, high amplitude, pulse which allows a good image of deep and complex structures to be obtained. The efficacy of this source is also proven for long offsets (wide-angle) data recording. In the frame of the EC program SINBUS (SINgle BUbble Source for seismic exploration of deep and complex structures), the prototype of a new guns monitoring system has been designed and realised, in order to correctly run the single bubble array. Single bubble/tuned array amplitude comparison has been performed on the near vertical reflection data acquired in two test sites. The analysis of the shot records and the stack sections show, for the single bubble source (SINBUS), the presence of higher energy at longer two-way-times. The high penetration of the SINBUS array could offer a more powerful offshore seismic source for the crustal exploration.