Under customs regulations, which is a requirement for a vessel operating within Customs waters?

Possessing valid licenses and documentation is essential for a vessel operating within Customs waters. This requirement ensures that the vessel complies with legal standards and regulations set forth by customs authorities. Valid documentation typically includes registration, permits, and compliance certificates that verify the vessel's adherence to both national and international maritime laws. Having this paperwork in order helps streamline the customs process, facilitates inspections, and ensures that the vessel and its cargo are compliant with all relevant laws and regulations.

The other options, while they may seem pertinent in a broader operational context, do not reflect the primary requirement under customs regulations for a vessel. For instance, reporting navigational changes may apply in certain situations but is not a specific customs mandate. Similarly, carrying certified customs agents or maintaining continuous communication might be important for safety and operational procedures, but these are not universally mandated under customs regulations. Therefore, the core requirement that ensures compliance with legal standards directly relates to possessing valid licenses and documentation.