Lights and wrecks - Only the most important lights and wrecks are shown on this chart. Boundaries - The International Boundaries shown on this chart are approximate only. Submarine cables - Not all submarine cables are charted correctly. See larger scale charts. Gas pipelines - For further details see larger scale charts. Minimum information area - In the coastal area within the depth contour of 30m, nautical information is minimum and inadequate to safeguard navigation. See charts at larger scale.