The minimum annual random drug testing rate is 50 percent of covered crewmembers, and serious marine incident testing is the only one of the three that covers alcohol as well as dangerous drugs.
What the rule requires
Who sits in the random pool
Most drug testing questions aimed at OUPV and Master 100 GT candidates turn on one thing: whether a named person is a covered crewmember. The regulation answers that with two different lists depending on the vessel, and the lists do not match.
On an uninspected vessel, a crewmember is covered if he or she is required by law or regulation to hold a license issued by the Coast Guard to perform those duties, performs duties and functions directly related to the safe operation of the vessel, performs the duties of a patrolman or watchman required by the chapter, or is specifically assigned the duties of warning, mustering, assembling, assisting, or controlling the movement of passengers during emergencies 46 CFR §16.230.
On an inspected vessel, the first hook is replaced: the crewmember occupies a position, or performs the duties and functions of a position, required by the vessel's Certificate of Inspection. The patrolman/watchman and emergency-passenger categories carry over unchanged.
There is no "directly related to safe operation" catch-all on the inspected side, and no COI to consult on the uninspected side. That is why the unlicensed deckhand on a six-pack charter is squarely in the pool — he handles lines, stands lookout and works the anchor, which is safe operation of the vessel, and no COI needs to name him.
The emergency-duty category is the one candidates skip. A crewmember whose only assigned emergency function is mustering passengers and getting them into life jackets is covered on the strength of that assignment alone, whatever the rest of the job description says.
Rate, selection and scheduling
The minimum annual percentage rate for random drug testing is 50 percent of covered crewmembers, except as adjusted by the Commandant. The employer must randomly select enough covered crewmembers during each calendar year to equal a rate not less than that minimum, and where a consortium runs the program the count may be worked per employer or across the whole consortium pool.
Selection must be by a scientifically valid method — a random number table, or a computer-based generator matched to Social Security, payroll or comparable identifying numbers. Every covered crewmember has an equal chance each time selections are made, and that chance continues throughout employment. The permitted alternative is to select one or more vessels periodically and test all covered crewmembers aboard, provided each vessel in the employer's program remains equally subject to selection.
Tests must be unannounced, and the dates spread reasonably throughout the calendar year. Employers may form or use sponsoring organizations, or hire contractors, to run the program.
The 50 percent figure moves only by Commandant action, on the industry-wide random positive rate drawn from drug MIS reports, published in the Federal Register and effective January 1 of the following year. From 50 percent it may be lowered to 25 percent when two consecutive calendar years show a positive rate below 1.0 percent; from 25 percent it goes back to 50 percent when any calendar year comes in at or above 1.0 percent.
The bar on serving
An individual may not be engaged or employed — including self-employment — on a vessel as master, operator or person in charge in a position for which a credential is required, unless all crewmembers covered by §16.230 are subject to that section's random testing requirements.
Read that as an operating restriction on you, not a paperwork burden on somebody else. Run your own boat, hire one deckhand, leave him out of a random program, and you are not lawfully employed as operator of that vessel.
You run an uninspected six-pack single-handed most days, but on charters you carry one unlicensed deckhand who handles lines and stands lookout. He is not in any random testing program. What is your status as operator?
You may not be engaged or employed, including self-employment, as operator, because §16.230(k) conditions that on all covered crewmembers being subject to the random testing requirements. The deckhand is covered: his duties are directly related to the safe operation of the vessel under §16.230(b)(2), and no license or COI position is needed to put him in the pool .
Pre-employment
No marine employer may engage or employ any individual to serve as a crewmember unless that individual passes a chemical test for dangerous drugs for that employer 46 CFR §16.210.
Two waivers exist, and they are alternatives — the applicant needs one, not both, and must produce satisfactory evidence of it. The employer may waive if the individual has either:
- Passed a chemical test for dangerous drugs required by Part 16 within the previous six months, with no subsequent positive drug tests during the remainder of that six-month period; or
- During the previous 185 days, been subject to a random testing program required by §16.230 for at least 60 days, without failing or refusing to participate in a chemical test required by Part 16.
The second path is the one working mariners actually use, and it has two numbers doing two different jobs: 185 days is the look-back window, 60 days is the minimum time in the pool inside that window.
An applicant for a deckhand job shows you a passing drug test dated seven months ago and a letter confirming he has been in a §16.230 random pool for the last 90 days. Must he test for you?
No — he satisfies the second waiver. Ninety days in a random program falls inside the previous 185 days and exceeds the 60-day minimum, so you may waive the pre-employment test on that evidence. The seven-month-old test is outside the six-month window and does nothing for him on its own .
After a serious marine incident
The marine employer must ensure that all persons directly involved in a serious marine incident are chemically tested for evidence of dangerous drugs and alcohol, in accordance with the requirements of 46 CFR 4.06 46 CFR §16.240.
Two words earn their keep there. All persons — not only the credentialed operator, not only whoever had the helm. And alcohol, which appears in none of the other testing requirements in this part.
§16.240 sets no timing and defines nothing. Everything procedural — who counts as directly involved, and how soon the specimens must be taken — lives in 46 CFR 4.06. Open it. This is an open-book module and guessing at a post-incident time limit is how candidates give away a question they could have looked up.
Telling it apart
The criterion that separates the three is the event that switches the test on, and it also fixes which substances get tested.
- Pre-employment — trigger is engagement or employment of an individual as a crewmember, and the test runs for that employer. Drugs only. Most often misfiled: a mariner with a recent passing test for a different company, who treats it as automatically portable when it only works through the §16.210(b) waiver.
- Random — trigger is membership in the covered pool plus unannounced selection during the calendar year. Drugs only. Most often misfiled: the steward or bartender with mustering duties, and the sole operator who assumes a one-boat, one-crew operation is outside the requirement.
- Serious marine incident — trigger is the incident itself, applied to every person directly involved. Drugs and alcohol 46 CFR §16.240. Most often misfiled: limited to licensed crew, or answered as drug testing only.
Working a question
You hold a Master 100 GT and operate your own uninspected charter vessel. You are hiring one deckhand for the season. He shows a passing chemical test taken four months ago for a previous employer, and states he has had no positive test since.
- Fix the vessel status first. Uninspected, so §16.230(b) governs the pool, not the COI list in §16.230(a). There is no COI to look at.
- Decide whether the deckhand is covered. He handles mooring lines, stands lookout under way and tends the anchor. Those are duties directly related to the safe operation of the vessel, so he is a covered crewmember. He holds no license, and that is irrelevant — (b)(1) and (b)(2) are separate hooks and either one is enough.
- Decide whether you are covered. You operate under a credential required by law for the service, so you are covered on the licensing hook. Self-employment does not exempt you.
- Handle the pre-employment test. His four-month-old passing test sits inside the six-month window. Get satisfactory evidence of the test result and of no subsequent positive; on that evidence you may waive the pre-employment test 46 CFR §16.210. "He told me" is not satisfactory evidence — with nothing in hand, test him.
- Get both of you into a random program before he starts work. A consortium or contractor is expressly permitted. Selections at not less than 50 percent annually, unannounced, and spread reasonably across the calendar year — not clustered in one month to clear the books 46 CFR §16.230.
- Work the incident branch. Mid-season you strike a jetty. If the casualty is a serious marine incident, you as marine employer must ensure every person directly involved is tested for dangerous drugs and alcohol under 46 CFR 4.06 46 CFR §16.240. That reaches the deckhand as well as you, and the definition and time limits come out of 4.06 — look them up rather than answering from memory.
Where candidates lose the point
Answering 25 percent for the random rate. The 25 percent figure is real but conditional: the Commandant may lower the rate to 25 percent only after two consecutive calendar years with an industry positive rate below 1.0 percent, published in the Federal Register. Unless the question hands you a published lower rate, 50 percent is the answer 46 CFR §16.230.
Blending the two pre-employment waivers into "six months in a random program." They are separate paths with separate arithmetic: six months since a passing test with no subsequent positive, or at least 60 days in a §16.230 random program within the previous 185 days. A distractor built on "185 days in a random program" or "six months in a pool" is designed to catch exactly that blend 46 CFR §16.210.
Treating a recent passing test as automatically good for the new job. §16.210(a) requires the test to be for that employer. Portability exists only through the waiver, the waiver is the employer's option, and the applicant must provide the evidence.
Answering post-incident testing as drugs only. Alcohol appears in §16.240 and nowhere else among these three requirements. If one option in a set says drugs and another says drugs and alcohol, the serious marine incident stem takes the latter.
Narrowing "all persons directly involved" to the licensed operator. The obligation is on the marine employer and it reaches everyone directly involved, unlicensed hands included.
Assuming random testing is an inspected-vessel matter. §16.230(b) is written for uninspected vessels, and §16.230(k) closes the loop on the self-employed operator. A distractor offering "uninspected vessels are exempt" is wrong on both counts.
Letting a crewmember know when the selection is coming, or bunching selections at year end. Tests must be unannounced and the dates spread reasonably throughout the calendar year.
Check yourself
You are the marine employer for two uninspected towing vessels. In a calendar year you have 10 covered crewmembers and the Commandant has published no adjusted rate. What is the minimum number of random drug tests you must conduct?
Five. The minimum annual rate is 50 percent of covered crewmembers, and you must select enough crewmembers during the calendar year to equal a rate not less than that minimum 46 CFR §16.230. Selections must also be unannounced and spread reasonably through the year, so five tests all taken in one week would not satisfy the section even though the count is met.
Your inspected small passenger vessel carries a bartender who holds no credential and stands no watch, but is assigned in the station bill to muster passengers and distribute life jackets. Is she in the random pool?
Yes. On an inspected vessel, a crewmember specifically assigned the duties of warning, mustering, assembling, assisting or controlling the movement of passengers during emergencies is covered, independent of any COI position or credential .
Your vessel is involved in a casualty that meets the definition of a serious marine incident. Which testing does the regulation require, and of whom?
The marine employer must ensure that all persons directly involved are chemically tested for evidence of dangerous drugs and alcohol, in accordance with 46 CFR 4.06 46 CFR §16.240. It is not limited to credentialed personnel, and it is the only one of these three requirements that includes alcohol.
An applicant tells you he was in a random testing program for 45 days three months ago before that company folded, and has had no test since. Can you waive his pre-employment test on that basis?
No. The random-program waiver requires at least 60 days in a §16.230 program within the previous 185 days; 45 days does not reach the threshold. He would need a qualifying passing test within the previous six months to use the other waiver, otherwise he must pass a test for you 46 CFR §16.210.
You run your own uninspected charter vessel with no other crew aboard. Does the random testing requirement touch you?
Yes. You are covered because a credential is required by law for your service, and §16.230(k) bars an individual from being engaged or employed, including self-employment, as master, operator or person in charge unless all covered crewmembers are subject to the random testing requirements .
Rather than drawing individual names, your company selects one vessel at random each quarter and tests everyone covered aboard her. Is that permitted?
It is, provided each vessel subject to the employer's test program remains equally subject to selection. The regulation offers vessel-based selection as an alternative to individual random selection, so long as all covered crewmembers aboard the selected vessel are tested .
A crewmember on your payroll is subject to random drug testing under the rules of two DOT agencies for you as a single employer. Which rate applies to him?
The rate established for the calendar year by the DOT agency regulating more than 50 percent of that crewmember's function . Where you as employer are subject to more than one agency's rules, you may instead keep separate pools by rate, or test everyone at the highest rate any of those agencies has set.
Check your understanding
One real exam question on Drug testing — pre-employment, random, post-incident, cited to source. No account.
Drug testing — pre-employment, random, post-incident
Random drug tests conducted under the marine employer's program must be ______.
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