In the event of compromised buoy functionality, what is essential for mariners to have?

When buoys are compromised in their functionality, having charted data and alternative navigation methods becomes essential for mariners. This is because navigational aids like buoys provide critical information about safe routes, hazards, and water depths. If such aids are not working correctly or are absent, it's crucial for mariners to rely on their navigational charts to identify their position, understand the surrounding environment, and make informed decisions about their course.

Charted data includes detailed maps of the waterways, which show the location of hazards, navigational channels, and safe anchorages. Alternative navigation methods could include the use of GPS technology, dead reckoning, or celestial navigation to determine position and track movement. This reliance on established navigation techniques helps ensure safety in situations where traditional buoy aids cannot be trusted.

In contrast, while communication devices, backup buoys, and fill-in markers may play roles in navigation, they do not replace the fundamental need for solid navigational skills and an understanding of charted information when primary aids fail.