Emergency power should be readily available to supply the
required emergency lighting, radio installation and navigation aids
for a minimum of 3 hours. As a minimum, the navigation aids to be
supplied by emergency power to include GPS, echo sounder and AIS.
The emergency power supply should be adequate to also supply any electrical
emergency equipment fitted, such as fire pumps, bilge pumps, watertight
doors, and rescue boat davit.
The emergency source of power should be independent of the main
power supply, external to the engine room, and with separate distribution.