Entry & progression
"Wiper, then Oiler, then QMED" is wrong. Oiler is a QMED rating. The ladder is Wiper → QMED, and the QMED comes in five flavours. Learn it this way and you will never be confused by a job advert again.
What a QMED is
46 CFR 12.501(a): a QMED is "any person below officer and above the rating of Coal Passer or Wiper…" — a Qualified Member of the Engine Department. That is a class of ratings, not a rating. Oiler sits inside the class. So does Junior Engineer. So do the other three.
WARNING — Say it out loud until it sticks Oiler is a QMED rating. You do not become an Oiler and then later become a QMED — you become a QMED as an Oiler. The endorsement on the credential reads QMED, and the rating is named on it. Anyone who tells you Oiler is a rung between Wiper and QMED is working from a bad source, and you should be sceptical of whatever else they told you.
The five current QMED ratings
12.501(b)(1), as amended by 89 FR 93101 of 25 November 2024, lists exactly five ratings in which a QMED endorsement may now be issued:
| QMED rating | The heart of it |
|---|---|
| Boiler Technician/Watertender | Boilers, feed water, combustion, steam plant |
| Oiler | The engineroom watch rating — rounds, readings, lubrication, standing by machinery |
| Junior Engineer | The general engine-room hand: machinery, systems, maintenance |
| Electrician/Refrigerating Engineer | Electrical plant, and refrigeration and air conditioning |
| Pump Technician/Machinist | Pumps, cargo and transfer systems, and the machine shop |
Each rating is a separate endorsement and each is examined separately. And then there is the one line that tells you where the ambition sits.
QMED — any rating
12.501(b)(1), in terms: *"Each QMED rating must be endorsed separately, unless the applicant qualifies for all QMED ratings, in which case the endorsement will read 'QMED—any rating.'"*
That is the one to aim at. QMED — any rating means you have qualified across the whole class, and it is the endorsement that makes you employable on anything with a machinery space. On a yacht, where the engineer is expected to be electrician, refrigeration hand, pump technician and machinist within the same afternoon, it is also the honest description of the job.
Why the error matters
Not because it is embarrassing. Because it wastes years. A mariner who believes Oiler is a separate rung below the QMED will spend six months trying to "get his Oiler" as though it were a lesser paper he could pick up on the way — when in fact he is looking at the QMED examination and its full requirements from the first day. Understand the shape of the ladder and you can plan the climb. Get the shape wrong and you will misjudge every step of it.