COMDTINST M16721.48 — Merchant Mariner Medical Manual

COMDTINST M16721.48 governs the evaluation of merchant mariners’ physical and medical conditions for medical certification.

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  • Publication number: COMDTINST M16721.48
  • Title: MERCHANT MARINER MEDICAL MANUAL
  • Date: 8/30/2019
  • Proponent: CG-MMC-2

View COMDTINST M16721.48 on armypubs.army.mil


It covers medical examinations, vision and hearing standards, physical abilities, certificates, endorsements, restrictions, waivers, and disqualifying conditions. It establishes evaluation criteria and documentation requirements for medical certification decisions.

Applies to: All Coast Guard Directorates, Offices, and Headquarters Units under the Assistant Commandant for Prevention Policy (CG-5P) should comply with the provisions of this Manual.

Topics covered

  • Merchant mariner medical certification
  • Vision and hearing standards
  • Physical ability guidelines
  • Medical certificate restrictions
  • Medical waivers
  • Cardiovascular conditions
  • Neurologic conditions
  • Psychiatric conditions

Questions and answers

What vision is required for a national endorsement or qualified deck rating?

In accordance with 46 CFR 10.305(a)(1), applicants for any national endorsement or qualified deck rating must have vision in at least one eye that is correctable to 20/40 or better. (paragraph 1)

How often must a first-class pilot serving on a vessel of 1600 GRT or more have a physical examination?

Title 46 CFR 11.709 requires that every credentialed first-class pilot serving as a pilot on a vessel of 1600 Gross Register Tons (GRT) or more have a thorough physical examination each year, that this physical examination meets the same requirements for originally obtaining the medical certificate as specified in 46 CFR, part 10, subpart C, and that it be recorded on an Application for Medical Certificate, Form CG-719K.

What is required to serve as a food handler?

In order to serve as food handler, a mariner must have the Stewards Department (F.H.) endorsement on the MMC and a medical certificate that does not exclude food handling. (paragraph 7)

How long can a time-restricted medical certificate remain valid?

Time-restricted medical certificates will expire either 1 year or 2 years from the date of examination, depending on the medical condition, condition status, and the need for periodic medical evaluations. (paragraph 5)

What is the minimum CPAP or BiPAP compliance for a medical certificate?

For purposes of obtaining or maintaining a medical certificate, minimum CPAP/BiPAP compliance is defined as proper use of the CPAP/BiPAP device for at least 4 hours per night (or per major sleep period) on at least 70% of all nights (or major sleep periods). (paragraph 2)

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