NAMS-CMS Marine Surveyor Exam Study Guide (2026)
Everything the NAMS Certified Marine Surveyor (NAMS-CMS): designations in Yachts and Small Craft, Cargo, Marine Warranty, Hull and Machinery 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 | Yachts and Small Craft: a 100-question CMS exam (NAMS study materials, June 2025). Question counts for Cargo, Hull and Machinery and Marine Warranty are not published; confirm with NAMSGlobal |
|---|---|
| Time | Not published by NAMSGlobal; confirm with NAMSGlobal |
| Passing score | At least 70% on each module and a cumulative average of at least 75% for the whole exam (NAMS membership application form). A failed module can be retaken 90 to 180 days after the first sitting |
| Format | Written technical exam in your chosen discipline, taken after the NAMS ethics test. NAMSGlobal does not publish the item format or reference rules; this prep uses 4-option single-best-answer items. It covers the written technical knowledge only, not sponsorship, report review or screening, and centers on the Yachts and Small Craft reference list with core Hull and Machinery, Cargo and Marine Warranty material |
| Certifying body | NAMSGlobal (The National Association of Marine Surveyors, Inc.) |
| Test provider | Arranged by NAMSGlobal after applicant screening and an ethics test; the technical exam must be taken within 90 days of notice of successful screening. Delivery method is not published; confirm with NAMSGlobal |
Mind map: the whole exam on one screen
Read the complete NAMS-CMS Marine Surveyor study notes for “Fuel, LPG/CNG and Ventilation Systems”
Our first full set of comprehensive notes, about 15 minutes of reading: Gasoline fuel systems (33 CFR 183, ABYC H-24) · Ventilation and ignition protection · LPG systems (ABYC A-1, A-26) · CNG and reporting gas findings, 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. Fuel, LPG/CNG and Ventilation Systems
From the NAMS Yachts and Small Craft reference list: 33 CFR 183 fuel and ventilation subparts, ABYC H-24 (gasoline fuel systems), H-2 (ventilation), A-1 (LPG), A-22 (CNG), A-26 (fueled appliances), A-14 (gas detection) and ignition protection. NAMSGlobal publishes no topic weights.
Key facts
- Compartments with permanently installed gasoline engines with cranking motors need powered ventilation and a label: run the blower 4 minutes and check for vapors before starting.
- Electrical parts in gasoline engine and fuel tank spaces must be ignition protected (33 CFR 183.410, tested to SAE J1171 or UL 1500).
- USCG fuel hose types: A1 fire-resistant for liquid fuel, A2 fire-resistant for vapor (fill and vent lines), B1 and B2 non-fire-resistant versions.
- Gasoline systems must not siphon fuel if a line is severed below the tank top: use an anti-siphon valve or electrically operated valve at the tank.
- Metallic fuel fill and tank components are grounded to dissipate static charge during fueling.
- LPG is heavier than air: cylinders go in a locker vapor-tight to the interior that drains overboard from its bottom, with a remote-controlled solenoid valve and a pressure gauge for leak testing.
- CNG is lighter than air, so CNG lockers and enclosures vent from the top.
Flashcards
Exam tip: Fuel and gas questions come down to two facts: gasoline vapor and propane sink, natural gas rises. Reason from where the gas goes before choosing an answer.
2. Electrical Systems, Batteries and Lightning Protection
ABYC E-11 (AC and DC systems), E-10 (storage batteries), E-13 (lithium batteries), E-30 (electric propulsion), A-27 (generator sets), A-31 (chargers and inverters) and TE-4 (lightning protection).
Key facts
- DC overcurrent protection within 7 inches of the source connection; 72 inches if attached directly to a battery terminal and sheathed throughout; 40 inches if sheathed and fed from another source. Starter conductors are exempt.
- Voltage drop: 3% for panelboard mains, navigation lights, bilge blowers and electronics; 10% for general lighting and other loads.
- Shore power neutral is grounded only ashore; onboard sources (generator, inverter, isolation transformer) ground the neutral at the source.
- An ELCI on the main shore feeder trips at 30 mA of leakage and is fitted within 10 ft of the shore power inlet.
- Batteries must be secured so they can't move more than 1 inch in any direction under a 90 lb pull or twice the battery weight, whichever is less, and positive terminals must be covered.
- Conductors are stranded copper, 16 AWG minimum in most circuits; solid wire is not accepted.
- Lithium installations need a battery management system that can disconnect the battery to protect it from out-of-range conditions.
Flashcards
Exam tip: For AC questions, ask where the neutral is grounded and where the green wire goes. Most AC deficiencies a surveyor finds come back to those two connections.
3. Corrosion, Cathodic Protection and Fastenings
ABYC E-2 (cathodic protection), A-28 (galvanic isolators) and the corrosion, bonding and fastening sections of NVIC 7-95 (wooden hulls), plus stray current and crevice corrosion from the H&M and Y&SC guides.
Key facts
- In a galvanic couple the less noble metal (the anode) corrodes. Zinc and aluminum alloy anodes suit salt water; magnesium is for fresh water only.
- Hull potentials are read with a silver/silver chloride reference electrode; protection means a shift of at least 200 mV more negative than the native potential, without overprotection.
- Overprotection damages aluminum (alkaline attack, paint blistering) and wood (soft, fibrous wood with white deposits around fastenings).
- Galvanic isolators block low-voltage galvanic current in the shore grounding conductor while passing fault current; isolation transformers break the path completely.
- DC stray current corrosion is fast and localized, often on one fitting, and comes from a fault on the boat or nearby.
- Stainless steel corrodes in crevices and oxygen-starved spots, such as under seals, in swage fittings and inside wood.
- Brass and manganese bronze lose zinc (dezincification) and turn pink and weak; silicon bronze and aluminum bronze resist it.
Flashcards
Exam tip: Decide first whether the corrosion is galvanic (two metals, slow and spread), stray current (a power source, fast and local) or overprotection (too much anode). The recommendation follows from the type.
Test yourself on these topics
Take the free 15-question NAMS-CMS Marine Surveyor test, then save your results to unlock your Readiness Score and the mistakes bank.
4. Hull Construction and Repair: FRP, Wood, Steel and Aluminum
NVIC 8-87 (FRP vessels), NVIC 7-95 (wooden hulls), NVIC 7-68 (steel hulls), ABYC T-1 (aluminum applications), ABYC H-3 (windows and hatches) and Transport Canada TP1332 construction standards.
Key facts
- FRP defects: gelcoat crazing and star cracks, stress cracks at hard spots, delamination, osmotic blisters and wet or rotted core.
- Moisture meters are comparative; confirm high readings with percussion sounding and, with the owner's consent, invasive checks.
Flashcards
Exam tip: On every hull question, ask what the material fails by: FRP by water and delamination, wood by rot and fastening failure, steel by wastage, aluminum by galvanic and poultice corrosion.
5. Regulations, Flotation and Fire Protection
33 CFR 183 (boats and associated equipment), 46 CFR 25 (uninspected vessels), ABYC S-7 (capacity labels), NFPA 10, 302 and 303, and the Transport Canada Small Vessel Regulations.
Key facts
- 33 CFR 183 capacity labels apply to monohull boats under 20 ft, except sailboats, canoes, kayaks and inflatables.
- Flotation for monohulls under 20 ft: basic flotation for inboards, sterndrives and outboard boats rated 2 hp or less; level flotation for outboard boats rated over 2 hp.
Flashcards
Exam tip: Regulation questions turn on length, propulsion type and build year. Write those three down from the stem before you look at the options.
6. Through-Hulls, Exhaust, CO and Rigging
ABYC H-27 (seacocks and through-hulls), P-1 (exhaust systems), A-24 and TH-22 (carbon monoxide), H-3 (glazing), T-5 (safety signs) and NVIC 02-16 (sail rigging and masts).
Key facts
- Underwater through-hulls need seacocks that show open or closed at a glance; gate valves are not seacocks.
- Hose clamps should be all 300-series stainless steel; below the waterline, two clamps are standard where the hose barb is long enough.
Flashcards
Exam tip: For any fitting below or near the waterline, ask what happens if it fails. That answers how serious the finding is and how you word it.
7. Hull and Machinery Surveys
From the NAMS Hull and Machinery study guide (16 chapters): hull girder strength, framing and double bottoms, welding and repairs, corrosion and coatings, stability and load line, bilge and watertight integrity, propulsion, diesel and electrical systems, towing, cargo and tank vessels, survey types and reporting. A separate fishing vessel guide covers that designation.
Key facts
- The hull is a girder: in hogging the deck is in tension and the bottom in compression; in sagging the reverse.
- Garboard, waterline and sheer strakes are high-concern areas, and their deterioration is structural, not cosmetic.
Flashcards
Exam tip: NAMS H&M questions reward thinking in load paths. A defect matters more when it sits in a member that carries hull girder or watertight loads.
8. Cargo and Marine Warranty Surveys
From the NAMS Cargo study guide (2026 revision: ethics and safety, containers, securing and dunnage, steel, bulk and liquid cargoes, draft surveys, moisture and ventilation, hatch covers, claims and insurance) and the Marine Warranty reference list (codes of practice, DNV-ST-N001 marine operations, tow manuals, cargo securing).
Key facts
- Draft survey quarter mean = (F + A + 6M) ÷ 8, then correct displacement for trim and dock water density.
- Containers carry a CSC Safety Approval Plate; the CTU Code covers packing and securing, and IICL criteria cover damage and repair.
Flashcards
Exam tip: Cargo questions usually ask who is responsible or what the evidence shows. Report what you observed and measured, and keep opinion clearly separate.
How to pass
- You need 70% on every module, not just 75% overall. A weak module fails you even with a strong total, so don't leave one area unstudied.
- Read the NAMS reference list for your discipline line by line. For Yachts and Small Craft that means about 25 named ABYC standards plus 33 CFR 183, 46 CFR 25 and four NVICs.
- Answer as a surveyor reporting a finding: what the standard requires, whether the item meets it, and how serious the deficiency is.
- Testing must happen within 90 days of passing screening, so start studying before you apply rather than after.
Frequently asked questions
How long should I study for the NAMS-CMS Marine Surveyor 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 NAMS-CMS Marine Surveyor 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: written technical exam in your chosen discipline, taken after the nams ethics test. namsglobal does not publish the item format or reference rules; this prep uses 4-option single-best-answer items. it covers the written technical knowledge only, not sponsorship, report review or screening, and centers on the yachts and small craft reference list with core hull and machinery, cargo and marine warranty material. Ask the ABYC Education Department which reference materials are allowed.
What score do I need to pass the NAMS-CMS Marine Surveyor exam?
At least 70% on each module and a cumulative average of at least 75% for the whole exam (NAMS membership application form). A failed module can be retaken 90 to 180 days after the first sitting. The exam has yachts and small craft: a 100-question cms exam (nams study materials, june 2025). question counts for cargo, hull and machinery and marine warranty are not published; confirm with namsglobal and a time limit of not published by namsglobal; confirm with namsglobal.
What are the most tested topics?
The outline covers fuel, lpg/cng and ventilation systems, electrical systems, batteries and lightning protection, corrosion, cathodic protection and fastenings, hull construction and repair: frp, wood, steel and aluminum, regulations, flotation and fire protection, through-hulls, exhaust, co and rigging, hull and machinery surveys, cargo and marine warranty surveys. Use the free practice test to see which ones you need most.
The premium NAMS-CMS Marine Surveyor study path
Premium NAMS-CMS Marine Surveyor 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
- 1Fuel, LPG/CNG and Ventilation Systems8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Notes free with an account
- 2Electrical Systems, Batteries and Lightning Protection8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 3Corrosion, Cathodic Protection and Fastenings8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 4Hull Construction and Repair: FRP, Wood, Steel and Aluminum8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 5Regulations, Flotation and Fire Protection7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 6Through-Hulls, Exhaust, CO and Rigging7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 7Hull and Machinery Surveys7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 8Cargo and Marine Warranty Surveys7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- Final step: 6 full mock exams100 questions each, timed like test day. Pass them, then book your exam.Premium
Get every note, flashcard and question
Premium Monthly
- One ABYC exam of your choice: any of the 10 certifications, from Marine Electrical to USCG Regulations
- 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 monthly until you cancel. Cancel in two clicks from your account; you keep access until the end of the month you've paid for. No minimum term.
Premium Yearly
- One ABYC exam of your choice: any of the 10 certifications, from Marine Electrical to USCG Regulations
- 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 NAMSGlobal (The National Association of Marine Surveyors, Inc.).