The 100ft array on Matapan was a bottom bounce sonar. Horizontal beams are generally deflected upwards to the surface by the temperature profile of the sea, while below a critical depth, the beams are deflected downwards. That creates a shadow zone which cannot be reached, except by a bottom bounce beam.
I was the designer of much of the electronics for directional control/stabalisation. Together with the project leader, we took the first segment of the array with the associated electronics to Lake Pend Oreille (Idaho) for testing in 1973.