NMEA NMET Exam Study Guide (2026)
Everything the National Marine Electronics Technician (NMET) tests, topic by topic: what each section covers, the facts that come up most, and how to study it. Pair it with the free 15-question practice test.
The exam at a glance
| Questions | 150 multiple-choice questions, drawn from the same pool of nearly 500 as the CMET exam |
|---|---|
| Time | 2 hours |
| Passing score | 80% (120 of 150) |
| Format | Closed book, proctored multiple choice; a standard calculator is allowed. Prerequisites: current AMEI and Advanced NMEA 2000 certificates at the time of the exam. No FCC licenses are required |
| Certifying body | National Marine Electronics Association (NMEA) |
| Test provider | Proctored by NMEA: online with NMEA staff, by mail to a library, learning center or college you nominate, at the NMEA Conference, or at the NMEA office in Severna Park, Maryland. Book at least 2 weeks ahead |
Mind map: the whole exam on one screen
Read the complete NMEA NMET study notes for “NMEA 0400 Installation Practice”
Our first full set of comprehensive notes, about 13 minutes of reading: Planning the installation · Penetrations and sealing · Cable support and protection · Commissioning and documentation, a worked exam example, the traps examiners use and a one-minute recap. Create a free account to read it and see how premium notes work before you decide.
1. NMEA 0400 Installation Practice
NMEA does not publish topic weights. It names the NMEA 0400 Installation Standard as the core study text for the shared CMET/NMET pool, so installation practice runs through questions on every system.
Key facts
- Plan the installation first: equipment locations, cable routes, power sources, antenna separation and compass safe distances.
- Seal every exterior penetration with a rated gland or seal and form a drip loop below it; protect cored decks from water ingress.
- Protect cables from chafe at edges and bulkheads with grommets or guards, and support them along the run.
- Leave service loops at equipment so units can be removed for service.
- Respect each device's compass safe distance when mounting near the steering compass or heading sensor.
- Keep antennas apart: radar beams away from GNSS and satcom antennas, VHF antennas separated from each other and from AIS.
- Test, commission and document: settings, offsets, software versions and a wiring diagram for the owner.
Flashcards
Exam tip: When two answers both work, NMEA 0400 questions usually want the one that is sealed, supported, serviceable and documented.
2. Power Distribution and Electrical Principles
Power distribution and electrical principles are named pool areas. Expect Ohm's law, voltage-drop limits and tests, fuse placement, batteries and noise.
Key facts
- Ohm's law: E = I × R; power P = E × I. A 120 W load at 12 V draws 10 A.
- Electronics circuits are designed for no more than 3% voltage drop; wire size from CM = (10.75 × I × L) ÷ E with round-trip L.
- A voltage-drop test under load finds high-resistance connections that a continuity test misses.
- Overcurrent protection sits near the power source and is sized to protect the wire.
- Electronics negatives return to the DC negative bus; bonding conductors are not current-carrying returns.
- Batteries in series add voltage; in parallel they add amp-hour capacity.
- Alternator whine that changes with RPM is conducted noise on power leads; isolate by switching sources off one at a time.
Flashcards
Exam tip: If the stem gives a voltage at the battery and at the device, work out the percentage drop before reading the options.
3. Marine Networks: NMEA 0183, NMEA 2000 and Ethernet
NMEA 0183, NMEA 2000 and Ethernet are named pool areas, and an Advanced NMEA 2000 certificate is a prerequisite. Expect topology rules, power and termination, and data faults.
Key facts
- NMEA 0183 is one talker to several listeners; two talkers on one input need a multiplexer.
- 0183 runs at 4800 baud, or 38,400 baud for high-speed sources such as AIS; ports must match.
- Common 0183 sentences: RMC (recommended minimum GNSS), GGA (fix data), HDG and HDT (heading), DBT (depth below transducer), MWV (wind), VDM and VDO (AIS).
- NMEA 2000 backbone: terminators at both ends only, drops up to 6 m each and 78 m total, backbone up to 200 m with mid or heavy cable.
- NMEA 2000 shield grounded at the power insertion point only; power near the center of the load so no device falls below 9 V.
- Common PGNs: 129025 position rapid update, 129026 COG and SOG, 127250 heading, 128267 water depth, 130306 wind.
- Ethernet segments run up to about 100 m; duplicate IP addresses and wrong subnets stop devices seeing each other.
Flashcards
Exam tip: Most NMEA 2000 faults are physical. Check voltage at the far device and resistance across CAN_H and CAN_L before touching settings.
Test yourself on these topics
Take the free 15-question NMEA NMET test, then save your results to unlock your Readiness Score and the mistakes bank.
4. Radar and RF Principles
Radar and RF principles are named pool areas. Even without FCC licenses, NMET candidates face the same radar and RF theory questions as CMET candidates.
Key facts
- Bearing discrimination comes from horizontal beamwidth: longer antennas give narrower beams.
- Range discrimination comes from pulse length: about 150 m per microsecond.
Flashcards
Exam tip: Ask whether the targets differ in range or in bearing. Range separation is pulse length; bearing separation is beamwidth.
5. Navigation Sensors and Autopilots
GPS, heading devices and autopilots are named pool areas. Expect sensor choice and placement, calibration, and tuning faults.
Key facts
- COG and SOG come from GNSS; heading comes from a compass or satellite compass. They differ in current, leeway and at low speed.
- Satellite compasses give true heading from two GNSS antennas and suit steel hulls.
Flashcards
Exam tip: Weaving or overshoot points to gain; a steady heading offset points to calibration or alignment.
6. Communications: VHF, DSC, AIS, SSB and Satcom
VHF, DSC, AIS, SSB and sat comm are named pool areas. NMETs install and troubleshoot these systems; only CMETs may repair the transmitters.
Key facts
- VHF: channel 16 distress and calling, channel 70 DSC only, 25 W high and 1 W low.
- DSC distress alerts carry position only when the radio has a valid GPS input or internal receiver.
Flashcards
Exam tip: If reception works but transmission doesn't, look at what transmission needs that reception doesn't: position, MMSI, antenna match or license-limited settings.
7. Displays, Wi-Fi, Computers and Sat TV
Video displays, computers, MFDs, Wi-Fi and Sat TV are named pool areas. Expect integration, signal and installation questions.
Key facts
- MFDs need ventilation behind the dash and a mounting location that respects compass safe distance and glare.
- Keep MFD and sensor software current; mismatched versions cause missing data or features.
Flashcards
Exam tip: For integration questions, check physical connection, then addressing, then software version.
8. Transducers and Hydroacoustics
Transducers and hydroacoustics are a named pool area. Expect hull-material choices, mounting location, frequency and calibration.
Key facts
- Hull material: plastic or stainless steel for aluminum hulls; bronze or stainless for wooden hulls; never bronze in aluminum or plastic in wood.
- Through-hulls need a fairing block on deadrise hulls so the face points straight down.
Flashcards
Exam tip: Pick the hull material first, then the mounting style, then the frequency. The exam often tests the first.
How to pass
- You get 48 seconds a question. Read the last line of a troubleshooting stem first so you know whether it asks for a cause, a first step or a fix.
- Because the pool is shared with CMET, FCC-style radio and radar theory still appears even though NMET doesn't require the licenses. Don't skip RF principles.
- The NMEA 0400 Installation Standard is the only text NMEA names. Know its wiring, routing, sealing and documentation practices well enough to apply them to any device.
- Your retake must be within 60 days and is included in the fee; after a failed retake you wait 12 months from the first attempt and pay again, so sit when ready.
Frequently asked questions
How long should I study for the NMEA NMET exam?
Most working candidates need 4 to 8 weeks at 45 to 60 minutes a day. Book your exam once your Readiness Score has stayed at 80 or higher for about a week.
Can I take the NMEA NMET exam online?
Yes. ABYC certification exams are taken with a proctor: online through a remote proctoring service, or for some certifications at the end of an ABYC class. Format: closed book, proctored multiple choice; a standard calculator is allowed. prerequisites: current amei and advanced nmea 2000 certificates at the time of the exam. no fcc licenses are required. Ask the ABYC Education Department which reference materials are allowed.
What score do I need to pass the NMEA NMET exam?
80% (120 of 150). The exam has 150 multiple-choice questions, drawn from the same pool of nearly 500 as the cmet exam and a time limit of 2 hours.
What are the most tested topics?
The outline covers nmea 0400 installation practice, power distribution and electrical principles, marine networks: nmea 0183, nmea 2000 and ethernet, radar and rf principles, navigation sensors and autopilots, communications: vhf, dsc, ais, ssb and satcom, displays, wi-fi, computers and sat tv, transducers and hydroacoustics. Use the free practice test to see which ones you need most.
The premium NMEA NMET study path
Premium NMEA NMET prep is studied one topic at a time. Each step starts with that topic's key notes and flashcard deck, then its own question sets of 25, so you master one topic before you move to the next. When every topic is strong, the 6 full mock exams show you're ready.
Your step-by-step study path
- 1NMEA 0400 Installation Practice8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Notes free with an account
- 2Power Distribution and Electrical Principles8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 3Marine Networks: NMEA 0183, NMEA 2000 and Ethernet8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 4Radar and RF Principles8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 5Navigation Sensors and Autopilots7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 6Communications: VHF, DSC, AIS, SSB and Satcom7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 7Displays, Wi-Fi, Computers and Sat TV7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 8Transducers and Hydroacoustics7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- Final step: 6 full mock exams150 questions each, timed like test day. Pass them, then book your exam.Premium
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- 3,000 practice questions + 6 full mock exams per exam
- 800 flashcards + 60 key notes per exam, by topic, plus mind maps
- Spaced repetition + mistakes bank
- Readiness Score & detailed reports
- Video lessons as they release
- Content updates during your access
- 5 bonuses: numbers and formulas sheet, standards map, study planner and more
- Pass Guarantee: complete the prep, pass or 100% back
Renews once a year until you cancel. We email you before each renewal. Cancel any time from your account; you keep access until the end of the year you've paid for.
Summarized from ABYC's official candidate information and the rules cited, checked November 2026. Confirm current requirements with National Marine Electronics Association (NMEA).