Seaworthiness and Stability Practice Questions for the MCA Orals
OOW Part A: 1 of the 15 questions, 50% to pass this topic
The real MCA oral is a spoken interview with an examiner; these questions are knowledge practice for it, each with a model answer.
60 test points across every Part A topic in 40 minutes, scored against the MCA’s minimum for each topic.
Free Seaworthiness drillA weight is shifted from a lower hold to the upper deck on the centreline. What is the effect on stability?
Seaworthiness in the MCA orals
Seaworthiness is one of the six 50% topics on OOW Part A and a large part of the oral. MIN 653 asks for a basic understanding of stability terms and the effect of loading, discharging and moving weights, free surface, list and loll, and preparing the ship for sea.
- On Part A
- 4 of the 60 test points (1 of 15 questions); you need 50%, 2 of 4
- In the oral
- The examiner can ask about any part of the syllabus, in scenarios. Say your answer out loud before you check it.
- Our drill
- 10 questions from 30 Seaworthiness questions, untimed, a model answer after every one; one free attempt, unlimited with a pass
Study notes
- Metacentric height GM = KM − KG. Positive GM gives a righting lever at small angles of heel; a large GM makes the ship stiff (quick, violent rolling), a small GM tender (slow, easy rolling).
- G moves towards a weight loaded, away from a weight discharged and parallel to the line joining the old and new positions of a shifted weight.
- Free surface in a slack tank raises the effective centre of gravity (a virtual loss of GM). It depends on the tank’s breadth (to the cube) and the liquid’s density, not its depth; longitudinal subdivision cuts it sharply.
- List is caused by G being off the centreline with positive GM. Loll is caused by negative initial GM: the ship flops to either side. Correct loll by lowering G (fill low double-bottom tanks one side at a time, starting on the low side, or remove high weights), never by moving weight across.
- The GZ curve shows the righting lever against heel; the IMO intact stability criteria set minimum areas under it, a minimum GZ and a minimum initial GM.
- Load line marks: the deck line, the Plimsoll disc and the lines TF, F, T, S, W and WNA. The ship must not be loaded so the applicable mark is submerged.
- Before sea and heavy weather: close watertight and weathertight doors, hatches and openings; secure cargo and loose gear; sound tanks; check freeing ports; reduce free surface; plan a heading and speed to ease motion.
Sit the Part A practice test under the clock
60 test points across every Part A topic in 40 minutes, scored against the MCA’s minimum for each topic.
Free Seaworthiness drillWhat the examiner looks for
- Stability terms and how loading, discharging and moving weights change G and GM (MIN 653).
- Free surface, its dangers at small angles of heel and the effect of tank subdivision and density.
- List against loll and how to correct each safely.
- Preparing the ship for sea and for heavy weather; reading the GZ curve and the loading instrument.
How to study it
- Draw KG, KM and GM on a ship section until you can explain them without notes.
- Practise the loll answer out loud; it is a classic oral question and the wrong correction capsizes the ship.
- Learn the load line marks with what each letter stands for.
- Take the seaworthiness drill until you score 80% or better.
Common questions
How many seaworthiness questions are on MCA Part A?
The six non-core questions on Part A come from the rest of the syllabus; the practice test gives each 50% topic one four-point question. The minimum is 50%.
What is the difference between list and loll?
A list comes from G being off the centreline while GM is positive; a loll comes from negative initial GM with G on the centreline, so the ship lies over to one side or the other. They are corrected differently: loll by lowering G.
60 test points across every Part A topic in 40 minutes, scored against the MCA’s minimum for each topic.
Free Seaworthiness drillThe other MCA orals topics
- International Collision Regulations
- IALA Systems of Buoyage
- Navigational Procedures
- Cargo Work
- Emergency Procedures
- Communication
- Regulation
- Other (Ship Handling, Meteorology, Safety and Security)
- Master: Law, Certificates and Surveys
- Master: Stability, Damage and Emergencies
- OOW Part A practice test (15 questions, 40 minutes)
- Mixed drill: every topic
Sources
- MCA: MIN 653 (M) Amendment 1, Deck Oral Exam Syllabus (OOW, Chief Mate and Master; expires 1 May 2027)
- MCA: MIN 690 Amendment 6, oral exam booking, Part A and Part B, resits and appeals
- MCA: MSF 4274, application for a deck oral examination (fees, oral pass validity)
- MCA: MIN 720 (M) Amendment 1, modernised officer qualifications and digital assessments (30 September 2026)
- MCA: MIN 654 (M) Amendment 1, Engineering and Electro-technical Officer Oral Exam Syllabus
- MCA: MSN 1781 (M+F) Amendment 3, the COLREG as applied in the UK
- IALA: Recommendation R1001, the IALA Maritime Buoyage System (Edition 2.0)
The MCA oral is a spoken interview with an MCA examiner. These are knowledge drills for it, with the model answer an examiner would expect after every question; they are not a simulation of the interview. The timed test copies the format of the OOW Part A computer-based exam. Original practice questions written from the MCA deck oral exam syllabus (MIN 653), the COLREG 1972 as applied by MSN 1781 and the IALA Maritime Buoyage System; they are not MCA questions or questions reported by candidates. The real oral is a spoken interview with an MCA examiner, and this is knowledge practice for it, not a simulation of the interview. Independent practice, not affiliated with or endorsed by the Maritime and Coastguard Agency.