Build your Deck test — required subjects and optional practice

NMC-source-based study guidance, not NMC approval of this site or your eligibility. Your current NMC evaluation/Approved to Test letter (ATT) and qualification history control the actual examination. Practical, sea-service, medical and STCW requirements remain separate.

Requirements reviewed 2026-10-12; guide: August 2014 edition currently linked by NMC. Required counts do not change when practice subjects are cleared or optional packages added.

Deck Rating: Able Seafarer (AB)

  • Able Seafarer (AB) preparation — AB category assigned by NMC: 2 required written modules — Q450, Q451. Q450 and Q451 are the two written AB subjects. Marlinespike demonstration and qualification as Lifeboat Operator or Lifeboat Operator-Limited are also required, or satisfied by applicable approved training; they are not counted as extra Q450/Q451 modules. Select your AB category below.
  • Separate endorsement preparation — Lifeboat Operator: 1 required written modules — Q445. NMC catalog written-study module. The September 2026 checklist also lists LB03/PSC assessment and approved-course pathways; follow your NMC ATT. Practical and eligibility requirements are separate.
  • Separate endorsement preparation — Lifeboat Operator-Limited: 1 required written modules — Q447. NMC catalog written-study module. The September 2026 checklist also lists LB04/PSC-Limited assessment and approved-course pathways; follow your NMC ATT. Practical and eligibility requirements are separate.

Third Mate, Unlimited

  • Original examination preparation — Near Coastal: 6 required written modules — Q100, Q111, Q112, Q113, Q115, Q116. Near Coastal and Oceans use different Navigation General modules. Oceans also retains the Near Coastal Navigation Problems subject.
  • Original examination preparation — Oceans: 7 required written modules — Q100, Q111, Q112, Q114, Q115, Q116, Q117. Near Coastal and Oceans use different Navigation General modules. Oceans also retains the Near Coastal Navigation Problems subject.
  • Applicable route addition — Near Coastal → Oceans: 2 required written modules — Q114, Q117. Qualifying existing-holder route addition only; not a shortcut for an original examination.

Second Mate, Unlimited

  • Qualifying document/sea-service upgrade — Near Coastal: 0 additional written modules (conditional). Zero additional written modules only after the qualifying prior operational-level examination and remaining requirements are met; NMC approval/ATT controls.
  • Qualifying document/sea-service upgrade — Oceans: 0 additional written modules (conditional). Zero additional written modules only after the qualifying prior operational-level examination and remaining requirements are met; NMC approval/ATT controls.
  • Examination-required preparation — Near Coastal: 6 required written modules — Q100, Q111, Q112, Q113, Q115, Q116. Near Coastal and Oceans use different Navigation General modules. Oceans also retains the Near Coastal Navigation Problems subject.
  • Examination-required preparation — Oceans: 7 required written modules — Q100, Q111, Q112, Q114, Q115, Q116, Q117. Near Coastal and Oceans use different Navigation General modules. Oceans also retains the Near Coastal Navigation Problems subject.
  • Applicable route addition — Near Coastal → Oceans: 2 required written modules — Q114, Q117. Qualifying existing-holder route addition only; not a shortcut for an original examination.

Chief Mate, Unlimited

  • Original examination preparation — Near Coastal: 8 required written modules — Q100, Q101, Q102, Q103, Q104, Q105, Q107, Q108. Near Coastal and Oceans use different Navigation General modules. Oceans also retains the Near Coastal Navigation Problems subject.
  • Original examination preparation — Oceans: 9 required written modules — Q100, Q101, Q102, Q103, Q104, Q106, Q107, Q108, Q109. Near Coastal and Oceans use different Navigation General modules. Oceans also retains the Near Coastal Navigation Problems subject.
  • Applicable route addition — Near Coastal → Oceans: 2 required written modules — Q106, Q109. Qualifying existing-holder route addition only; not a shortcut for an original examination.

Master, Unlimited

  • Qualifying document/sea-service upgrade — Near Coastal: 0 additional written modules (conditional). Zero additional written modules only after the qualifying prior management-level examination and remaining requirements are met; NMC approval/ATT controls.
  • Qualifying document/sea-service upgrade — Oceans: 0 additional written modules (conditional). Zero additional written modules only after the qualifying prior management-level examination and remaining requirements are met; NMC approval/ATT controls.
  • Examination-required preparation — Near Coastal: 8 required written modules — Q100, Q101, Q102, Q103, Q104, Q105, Q107, Q108. Near Coastal and Oceans use different Navigation General modules. Oceans also retains the Near Coastal Navigation Problems subject.
  • Examination-required preparation — Oceans: 9 required written modules — Q100, Q101, Q102, Q103, Q104, Q106, Q107, Q108, Q109. Near Coastal and Oceans use different Navigation General modules. Oceans also retains the Near Coastal Navigation Problems subject.
  • Applicable route addition — Near Coastal → Oceans: 2 required written modules — Q106, Q109. Qualifying existing-holder route addition only; not a shortcut for an original examination.

AB and QMED rating study guidance

A real route into the Merchant Marine. Ordinary Seafarer (OS) and Wiper are entry-level endorsements without a professional examination or qualifying sea-service requirement. AB and QMED are skilled national ratings, not officer licenses. Medical, drug-testing, application, security and employer requirements still apply. NMC entry-level checklist.

Able Seafarer (AB): deck skills and two written subjects

Formerly called Able Seaman. Q450 Navigation and Rules of the Road and Q451 Deck General and Safety are the two AB01 written modules. The NMC-linked examination guide lists 50 questions and a 70% passing score for each. These are official examination-format figures, not the length of your custom Mariner practice test.

  • Q450: nautical terms, compass basics, vessel lights and shapes, sound signals, aids to navigation and launching-device operation.
  • Q451: knots and seamanship, deck machinery and ground tackle, anchoring and emergency towing, pollution prevention, person-overboard response, firefighting, lifesaving equipment and survivor care.
  • Separate AB02 practical: the linked guide specifies one of two splices in 15 minutes, plus four required and six additional knots, bends or hitches in a separate 15 minutes. The four required are square knot, clove hitch, sheet bend and French bowline. Reading or answering a diagram question is not a substitute for making the knots.
  • Lifesaving qualification: national AB applicants must qualify as Lifeboat Operator or Lifeboat Operator-Limited, as appropriate. The practical, approved-course and vessel-specific pathways are separate from Q450/Q451.
  • Exam-room reference: the current Q450 sample dated August 27, 2026 expressly permits only The American Practical Navigator (Bowditch), Volume II. Do not assume a Navigation Rules book is allowed. Check the current NMC examination instructions.

Service is category-specific. Unlimited, Limited, Special, OSV, Sail and Fishing Industry are the six categories in 46 CFR 12.401. The active NMC checklist applies temporary service figures only to applications processed December 22, 2023 through December 22, 2026: 540 days Unlimited, 360 Limited, 180 Special/OSV/Sail/Fishing. These are not timeless rules; course credit and the NMC evaluation control. AB-MODU is separately listed on the checklist with a Marine Safety Manual basis, not a seventh category in §12.401.

National AB is not automatically STCW Able Seafarer-Deck. Seagoing service may require RFPNW, Basic Training, competency assessments and the appropriate survival-craft qualification. Able Seafarer-Deck normally requires 18 months of deck service while RFPNW-qualified, or 12 months with approved training; §12.603 and applicable crossover provisions control.

NMC AB checklist · National AB requirements · Category service rules · Written and practical requirements · STCW Able Seafarer-Deck · Lifeboat Operator checklist

Practice wisely: samples are not the whole examination bank

Mariner retains the current sample sets: 50 source occurrences each for Q450/Q451, and 70 each for Q800–Q808. The October 14 release verified 98 ready AB occurrences and 611 ready QMED occurrences; the unchanged exact-duplicate rule yielded 506 combined QMED practice entries. These dated coverage figures do not establish a complete national question bank. Ready counts can vary by selection and later separately approved publications. Archived Engine/Deck practice is broader material, not a fully mapped QMED/AB-only archive.

Plan for the missing experience: use the NMC subject outlines as your checklist, learn practical skills hands-on, study applicable training material and take approved courses where needed. Similar engineering or safety concepts may overlap with officer study; no “zero question overlap” claim is made.

Official sample PDFs for your study plan

Junior Engineer Q800 and Oiler Q804 emphasize plant and auxiliary systems; Q801 and Q805 also cover electrical, tools, maintenance and safety topics. These broad guides are not fixed subtopic question weights. Use the official module outlines. NMC examination-room materials and module-specific instructions, not a study app, decide allowed books and references. NMC examination-room materials.

Drawings: open the official source, keep your place here

For exactly matched figures, Study mode can open the USCG-hosted PDF at the drawing's page in a separate tab. Phone viewers may ignore the page target, so the figure ID and page number are shown. The official samples also include answers: reference links are not presented as an answer aid during examination-style testing. Mariner does not copy, crop or frame reproduction-restricted plates. Original teaching diagrams require independent authorship and technical alignment, not tracing a copyrighted picture.

Source review: October 15, 2026. NMC's index was refreshed September 2026; its still-linked administration guide is the August 2014 edition. Current sample dates and current CFR/checklists are distinguished from that older guide. This is independent study guidance, not USCG approval, credential eligibility or a guarantee of passing. Your current NMC evaluation and Approved to Test letter control.

Official module outlines and sample examinations · NMC examination guide (2014 edition) · Copyright Office: government works and reproduction rights

Official NMC examination guide · USCG conditional examination/upgrade requirements · 12 free guided study samples

Short guest previews and custom mixes are practice, not the complete official NMC examination. Full ready-question counts open after login; missing coverage remains visible.