The International Hydrographic Organization (IHO) issued a safety notice about reliable operation of ECDIS. It states about one-third of the various type-approved ECDIS for which it has received reports appear to function as expected. Another third display all significant underwater features, but the isolated danger symbol required to be shown under certain conditions is not always used. Most of the remaining third failed to display some significant underwater features in the “Standard” display mode. Under various conditions, mostly related to safety depth settings and other variable factors, these underwater features can include some types of wrecks and other obstructions. All of these features are displayed in the “Full display” or “All display” mode. One manufacturer, though, Japan Radio Co. Ltd. (JRC) confirmed that earlier versions of its ECDIS will not display some types of wrecks and underwater obstructions in any display mode. JRC has issued a notice alerting its customers and will make an upgrade package available shortly. Mariners using ECDIS should check their ECDIS equipment using the IHO ENC Data Presentation and Performance Check. Mariners should contact the ECDIS manufacturer if the equipment does not operate properly and should exercise appropriate caution until the issue is resolved.

IHO Circular Letter 33/2012 (3/14/12).

Note: It is premature to discard your paper charts and sextants! Complicated electronic systems induce excessive reliance and can fail you in unexpected ways.