How long must an Oil Record Book be preserved after the last entry?

The Oil Record Book is a crucial document for tracking oil transfers and discharges on a vessel, ensuring compliance with MARPOL regulations. It must be preserved for a minimum of three years after the last entry to allow for adequate inspection and verification by marine authorities. This timeframe ensures that there is a sufficient record available for review in case of any incidents or audits concerning oil pollution and operational practices. Keeping the records for three years helps maintain accountability and supports environmental protection efforts by ensuring that vessels adhere to standards designed to minimize oil discharge into the marine environment.