The Mariner's Guide to Marine Communications Plotting Tools ensuring that the environment is ensuring that the environment is protected and that those impacted by potential disasters can take swift action Indispensable Strait is a standard nautical chart d and revised in February 2007 with the introduction of the second edition which adds material covering regulatory changes like Ship Security Alert Systems and developments in communications which include new networks This Guide has been written primarily for Deck Officers keeping bridge watches at sea and other persons who have to manage and use the radio satellite communications equipment onboard a modern merchant ship