How long must the GMDSS radio log be retained on board before sending it to the shoreside licensee?

Correct Answer: Option B — At least 30 days after the last entry

FCC regulations under 47 CFR Part 80 require the GMDSS radio log to be retained on board for at least 30 days after the last entry before disposition or sending to a shoreside licensee, ensuring ready availability for safety audits and communications compliance inspections.