Airguns are used primarily to generate signals in marine seismics. Depending on the target to be resolved those airguns are towed behind the vessel either as one airgun or several in a cluster or tuned array. Umbilical cords supply the airguns with pressurised air, which is released by a trigger pulse in specific intervals. This then generates the seismic wave.
Airguns have different chamber sizes, which are chosen in relation to the objectives, i.e. target size and depth. Tow depth and distance to the vessel as well as the trigger interval are also dependant on the target depth and size.