What is an adequate independent back up arrangement?
Only a type approved ECDIS operating with up to date ENCs and with appropriate back up may be used to replace all paper charts on a vessel. Where ENCs are not yet available, IMO regulations allow Flag States to authorise the use of RNCs (together with an appropriate folio of paper charts) – see below. Note that in all other cases the vessel must carry all paper charts necessary for its intended voyage. The IMO Performance Standards therefore require that the “overall system” include both a primary ECDIS and an adequate independent back up arrangement that provides an independent facilities enabling a safe take over of the ECDIS functions in order to ensure that a system failure does not result in a critical situation and a means to provide for safe navigation for the remaining part of the voyage in case of ECDIS failure. There are two commonly accepted options: A second ECDIS, connected to an independent power supply and a separate GPS position input or an appropriate up to date folio
