The Deck Officer Ladder: Third Mate to Master

By Captain Mike · 50 years at sea · former MITAGS faculty
Checked against 46 CFR and NMC guidance · October 2026

The short answer

You take two Coast Guard exams in your deck officer career: one for Third Mate and one for Chief Mate.
The Third Mate exam also covers Second Mate. The Chief Mate exam also covers Master.
Between exams, sea time moves you up. There's no program to sign up for.
Before the Chief Mate exam, you need a set of required courses.
Keep your own record of every trip. Don't count on a company to have it later.

The ladder

Third MateExam 1

Second MateSea time only

Chief MateCourses + Exam 2

MasterSea time only

What to do at each step

Get to Third Mate

Three ways in: hawsepipe on your own, an optional AB-to-Mate program at a maritime school (faster, but it costs money and you have to be accepted), or a maritime academy. All three end with the same exam. Along the way you'll also complete required courses such as Radar Observer → and Advanced Fire Fighting →

Sail as Third Mate, then get Second Mate

Stand your watches for about a year. Send in your sea time and Second Mate is issued. No new exam.

Take the courses, then the Chief Mate exam

After about a year as a watch officer holding Second Mate, you can go for Chief Mate. Take the required management courses while you're still sailing as Second Mate, so they're done when your time is. Then sit the exam.

Sail as Chief Mate, then get Master

About a year as Chief Mate and Master is issued. No new exam. Some of your earlier mate time can help shorten this. See "Exact sea time" below.

From the Captain: keep your own sea-time record. Most companies will give you a good sea-service letter. Not all of them will, and the company you sailed for five years ago may have been sold, merged or stopped answering the phone by the time you need it. After every trip, write down the vessel, official number, tonnage, route, your position, your sign-on and sign-off dates and the watch system. Keep copies of every discharge and letter in two places. Ask for your letter before you leave the ship, while the Master who can sign it is still aboard. Sea-service letter template →

The fine print

For when you're ready to file. Requirements change, so confirm every number against the current NMC checklist.

1Exact sea time for each stepWhat the regulations require, and the two-for-one options

Moving up to	Sea time required	Exam
Second Mate	1 year as a watch officer (OICNW) on ocean self-propelled vessels while holding Third Mate. Or: 12 months total with at least 6 as a watch officer, with Able Seafarer time counted two-for-one, up to 6 months of substitution 46 CFR 11.406	None, if you passed the operational-level exam
Chief Mate	1 year as a watch officer on ocean self-propelled vessels while holding Second Mate 46 CFR 11.405	Management-level exam (covers Master too)
Master	1 year as Chief Mate. Or: while holding Chief Mate, 12 months total with at least 6 as Chief Mate, with Second or Third Mate time counted two-for-one 46 CFR 11.404	None, if you passed the management-level exam

No new exam for Second Mate or Master: 46 CFR 11.903(c).

2Courses required before Chief MateThe STCW management-level training

For the STCW Chief Mate endorsement 46 CFR 11.307:

Advanced shiphandling
Advanced stability
Advanced meteorology
Leadership and managerial skills
Search and rescue
Management of medical care
ECDIS, ARPA and GMDSS where they apply

The NMC checklist is the authority on the exact set for your endorsement. National vs. STCW →

3How a day of sea time is counted8-hour days, time-and-a-half, two-for-one, inland time

A day is 8 hours of watchstanding or day work, not counting overtime. The Coast Guard counts a month as 30 days and a year as 360 46 CFR 10.232.

Time-and-a-half. A 12-hour day counts as 1½ days only on vessels whose Certificate of Inspection authorizes a two-watch system, such as some crew boats, supply boats and towboats. On a normal three-watch ship, a day is a day.

Two-for-one. Where it's allowed, time in the rank below counts half. Example for Master: 6 months as Chief Mate plus 12 months as Second Mate (worth 6) makes the 12 months.

Waters. Great Lakes time counts day for day. Other inland time counts day for day for up to half the total.

Recency. The regulation asks for 3 months of service in the 3 years before a raise of grade. CG-MMC Policy Letter 02-25 extended that to 7 years for national officer endorsements.

4Traps on the way upMistakes that cost mariners months

Claiming time-and-a-half on a three-watch ship. The evaluator will count those 12-hour days as one day each.
Counting Second Mate time day for day toward Master. It counts half, and only after you hold Chief Mate with at least 6 months in that job.
Leaving the management courses until last. That can cost months.
A letter that doesn't state your position. If it isn't on paper, it doesn't count.
Chasing letters from a company you left years ago. Get them as you go.
Forgetting tonnage. Tonnage limits follow you up the ladder. Vessel tonnage & your license →

5Official sourcesRegulations and NMC guidance

Ready to apply? Applications now go through Navita, the Coast Guard's online credentialing system. It changes how you apply, not what you need. Navita: what changed →