BUTEC was established in the Inner Sound by the Ministry of Defence in the 1970s, the location chosen because of its sheltered, deep water, soft sea-bed and low levels of acoustic disturbance.

Together the area provides a controlled safe environment for a variety of trials and training activities, including airborne, surface and sub-surface assets, weapons and targets.

The noise range is about a mile long and divided into blocks 50 yards wide (labelled A to Z) within which is a large array of sensors.

If the boat does not achieve its expected aural signature, it is not permitted to start active patrols.

[8] Upcoming range activities are published in the local newspaper West Highland Free Press.