Ship types and structure
Ships are built for a job: cargo ships (containers, bulk grain or coal), tankers (oil, gas, chemicals), passenger ships and fishing vessels. All share a basic body.
- Hull: the watertight steel body below the deck.
- Bow is the front, stern the back. Port is the left side and starboard the right, when you face the bow.
- Keel: the strong backbone along the bottom.
- Deck: the floor on top. Bridge: the control room for steering. Engine room: engines and machines, usually at the back.
- Bulkheads: steel walls across the hull that make compartments.
Ship equipment
- Anchor and chain: hold the ship in place.
- Mooring ropes and winches: tie the ship to the quay.
- Rudder and propeller: steer and push.
- Navigation: compass, radar, GPS, echo sounder (depth), charts.
- Lifesaving: lifeboats, life rafts, lifejackets, lifebuoys, flares.
- Fire fighting: pumps, hoses, extinguishers, alarms.
- Cargo gear: cranes, derricks, hatches.
Shipboard organisation and duties
The master (captain) is in charge of the ship and everyone on it.
- Deck department (led by the chief officer): navigation watch on the bridge, steering, cargo work, mooring, ship upkeep. Crew: officers, boatswain (bosun), able seamen.
- Engine department (led by the chief engineer): main engine, generators, pumps, boilers, cooling. Crew: engineers, oilers, fitters.
- Catering and hotel department: cook, stewards.
The crew works in watches (for example 4 hours on, 8 hours off) so someone is always alert. A ship uses a muster list that says who does what in an emergency.
Damage control, health and safety
Damage control means stopping damage from spreading. The crew closes watertight doors, plugs or patches holes, uses pumps to remove water and fights fires. Because of bulkheads, a flooded compartment alone does not sink the ship; ships are designed to survive some flooded compartments.
Safety drills: fire drill, abandon-ship drill and man-overboard drill are done regularly. Personal safety: helmet, boots, gloves, lifejacket, harness for work at height, permission (permit to work) for dangerous jobs, safe lifting. Health: clean food and water, first aid kit, rest hours, medical help by radio.
Maritime laws
Ships sail between countries, so rules are made by the International Maritime Organization (IMO) and followed by member states.
- SOLAS: safety of life at sea (lifesaving equipment, fire safety, radio).
- MARPOL: stops pollution of the sea by oil, garbage and sewage.
- COLREGs: rules to avoid collisions: lights, signals, who gives way. Red light on port, green on starboard, white light at the mast.
- STCW: training and certificates for seafarers.
- ISPS code: ship and port security (access control, guards, alert system).
Maritime English
Crews come from many countries, so they use plain, short Standard Marine Communication Phrases. Rules: speak slowly, say one thing at a time, repeat numbers, confirm by repeating back.
- "Say again, please." means please repeat.
- "Mayday" (said three times) = life in danger. "Pan-pan" = urgent, but no immediate danger. "Securité" = safety message.
- Directions: port, starboard, ahead, astern. Speeds: slow ahead, half ahead, full ahead, stop.
- Always answer with the same word, for example "Understood", "Wait".
Key formulas and definitions
- Floating: weight of the ship = weight of water it pushes aside
- Reserve buoyancy = volume of the watertight part above the water line
- Watch system example: 4 hours on, 8 hours off
- Colour code: port = red, starboard = green
Worked examples
1. You stand on the deck facing the bow. Which side is port?
Port is the left side. Starboard is the right side.
2. A ship has 6 equal watertight compartments and can stay afloat with any 2 flooded. A collision floods 3 neighbouring ones. What should the crew do first?
The ship is beyond its safe limit, so the crew must start abandon-ship procedures while using pumps and sealing the doors.
3. A crew keeps a 4-on-8-off watch. How many hours does each person stand watch in 24 hours?
One watch cycle is 12 hours with 4 on, so in 24 hours: 2 watches × 4 = 8 hours on watch.
4. You see only a green light ahead. Which side of that ship are you looking at?
Green is on the starboard (right) side of the other ship, so you see its starboard side.
Common mistakes
- Mixing up port and starboard. Remember: port = left = red.
- Thinking a ship sinks as soon as one compartment is flooded.
- Saying "Mayday" for a small problem. Mayday is only for danger to life.
- Believing the captain alone runs the ship. Departments and watches share the work.