To qualify for the GS-13, you must have at least one year of experience equal or equivalent to the GS-12, it must include: Technical experience conducting marine regulatory reviews, inspections, surveys, audits, vetting, clearances, and incident investigations of ship structures, control systems, propulsion systems, safety systems, or machinery as a senior level marine surveyor, inspector, engineer, auditor, advisor; senior shipboard captain, senior shipboard engineer, senior deck (navigational) officer, or similar. To qualify for the GS-12, you must have at least one year of experience equal or equivalent to the GS-11, it must include: Technical experience conducting marine regulatory reviews, inspections, surveys, audits, vetting, clearances, or incident investigations of ship structures, control systems, propulsion systems, safety systems, or machinery as a marine surveyor, inspector, engineer, auditor, advisor; shipboard engineer officer, deck (navigational) officer, or similar in the public or private sector.