Maritime Knowledge Base
Browse questions and answers across marine machinery, merchant navy careers, shipboard operations and maritime glossary terms.
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Marine Machinery
Troubleshooting guides for pumps, boilers, purifiers, compressors and auxiliary systems.
Merchant Navy Careers
Questions about joining the merchant navy, exams, cadetships, ranks and sea-time.
Maritime Glossary
Plain-English definitions of shipping, engine-room, navigation and regulatory terms.
Shipboard Operations
Practical Q&A for watchkeeping, safety, maintenance routines and onboard documentation.
Results for "AIS"
What are the four stages of passage planning (appraisal, planning, execution, monitoring)?
Passage planning follows four stages — appraisal, planning, execution and monitoring — that together prepare and carry out a safe voyage from berth to berth.
Merchant Navy CareersWhat is a Certificate of Competency (CoC) and how do I get one?
What a CoC is, the STCW rank levels it comes in, and the sea time, courses and exams needed to earn and raise one.
Shipboard OperationsWhat is the man overboard (MOB) procedure on a ship?
When someone falls overboard, immediate, drilled actions — raising the alarm, marking the position and turning the ship back — give the best chance of recovery.
Shipboard OperationsWhat is the correct enclosed space rescue procedure?
Enclosed space rescue must never be attempted by rushing in — it demands raising the alarm and using a trained team with breathing apparatus and retrieval equipment.
Shipboard OperationsWhat is a toolbox talk and when is it done?
What a toolbox talk is, when it happens before shipboard work, and how it turns the risk assessment and permit into a shared plan.
Marine MachineryWhy is my fuel or oil purifier not separating properly?
The usual causes of poor purifier separation — feed rate, temperature, gravity disc and water seal, sludge and bowl condition — and how to work through them one at a time.
Marine MachineryWhy is my main engine jacket cooling water temperature high?
Working through high jacket-water temperature — flow, the cooler, the sea and central-cooling side, thermostats, air locks and load.
Merchant Navy CareersWhat are the disadvantages and challenges of a merchant navy career?
A merchant navy career has real downsides — long separation from family, isolation, demanding work and health pressures — that anyone considering it should understand.
Shipboard OperationsWhat is a permit to work (PTW) system on ships?
A permit to work is a formal written authorisation that controls hazardous, non-routine jobs by confirming the hazards are assessed and the right precautions are in place.
Marine MachineryWhy is the exhaust temperature high on one main engine unit?
A high exhaust temperature on a single cylinder points to that unit's combustion, injection or exhaust valve — a deviation from the others is the key diagnostic clue.
Marine MachineryWhy is the main engine lubricating oil pressure low?
Low lubricating oil pressure is a serious alarm that threatens the bearings — the cause is usually in the pump, the filters, the oil itself, or a leak.
Marine MachineryWhy won't two generators share load equally when running in parallel?
When paralleled generators fail to share load evenly, the fault lies in the governor and speed settings for active power, or the excitation for reactive power.
Marine MachineryHow does a marine boiler work?
A marine boiler generates steam by transferring heat to water — this covers the working principle and the difference between oil-fired and exhaust-gas boilers.
Marine MachineryHow does a marine fresh water generator (evaporator) work?
A fresh water generator makes drinking and technical water from seawater by boiling it under vacuum using waste heat from the engine, then condensing the vapour.
Shipboard OperationsHow is cargo secured and lashed on a ship?
Cargo is secured against the forces of the ship's motion using lashings, twistlocks and dunnage, in accordance with the ship's approved Cargo Securing Manual.
Marine MachineryHow does a marine air compressor work and why is it needed?
A marine air compressor squeezes air in stages to high pressure and stores it in receivers, chiefly to provide the starting air that turns large diesel engines over.
Shipboard OperationsHow does marine radar and ARPA work?
Marine radar detects other ships and land by transmitting radio pulses and timing their echoes; ARPA automatically tracks targets and calculates the risk of collision.
Shipboard OperationsWhat is a gyrocompass and how does it differ from a magnetic compass?
A gyrocompass is a navigation instrument that uses a fast-spinning gyroscope to find and hold true north, unaffected by the ship's magnetism, providing a true heading to the ship's systems.
Marine MachineryWhat is a central cooling system on a ship and why is it used?
A central cooling system uses seawater to cool a closed freshwater circuit, which in turn cools the machinery — reducing seawater corrosion and fouling in the equipment.
Shipboard OperationsWhat are the classes of fire and which extinguishers are used on ships?
Fires are grouped into classes by what is burning, and each class needs the right extinguishing agent — using the wrong one can be ineffective or dangerous.
Shipboard OperationsWhat is a Safety Management System (SMS) on a ship?
A Safety Management System is the documented set of policies and procedures, required by the ISM Code, by which a company manages the safe operation of its ships and prevention of pollution.
Marine MachineryWhat is a governor on a marine engine and what does it do?
A governor automatically controls an engine's speed by adjusting the fuel supply to match the load, keeping the engine at the required revolutions or a generator at constant frequency.
Shipboard OperationsWhat safety precautions are taken for working aloft on a ship?
Working aloft — up the mast, funnel or high structures — demands a permit, a safety harness, secured tools, and control of hazards such as radar, whistle and overside work.
