The tapwire is a device developed by the dwarven and duergar engineers of Barazar El to aid in coordinating between their deep sea settlements. Thin metal cabling, protected from the elements by thick insulation and coating, connects all of the underwater cities, with the central hub of the network in Pelagic Frontier. Magical pulses are transmitted along the tapwire and received quickly at all other settlements despite the great distances between them. The tapwire cables are inspected and maintained regularly. The tapwire is used on an everyday basis for regular communication between the settlements, though use is usually restricted to practical matters.