Starboard vs Portside

Starboard vs Portside – The Ultimate FAQ Guide

If you want to compare starboard vs portside, then this guide has all information you’re looking for.

From basic definition, uses, to origin of the terms – you’re going to learn everything about starboard vs portside here.

Keep reading to learn.

What is Starboard?

This refers to a nautical term for navigation that unambiguously references the right side of a vessel.

This is normally achieved by an observer aboard a vessel.
The observer uses this navigational term while facing the front of the bow.



What does Portside mean?

This is a nautical term that unambiguously references the left side of a vessel.

This is done while observing the bow.
Similarly given when facing the front of a vessels’ bow.

What is the difference between Starboard and Portside?

Starboard is the right side of a vessel.

Portside is the left side of a vessel.

Starboard is denoted mostly by the color green.

Portside is denoted by the color red.

Port side


What is the Origin of the Term ‘Starboard’?

The etymology of starboard comes from steorbord.

Steorbord means the direction which the ship is steered.

Steor means steer.

Bord refers to side of a boat.

What is the Origin of ‘Portside’?

Initially it was called backboard.

It later transitioned to ladder board meaning to load.

Do Cargo Ships always Dock at Portside?

Cargo ship

Cargo ship

The position to dock can be on either portside or starboard.

The captain of the ship has the discretion to choose where to dock.

Some other factors that may determine which side you dock on are:

  • The government regulations for a particular country or region.
  • Layout of the port area.
  • The direction that the boat is sailing in.

When should you Use Portside?

A port is a term in navigation that you will use in seafaring.

When one is facing the bow or front side of the ship, the port side is the on the left side.

You should use the term portside while navigating the sea and indicating to turn to the left direction.

During the past, ships would approach the port when the left side is facing the dock.

The reason for this was because the rudder was always on the right side of the ship.

When should you use Starboard?

Starboard, just like portside, is also a terminology that you will use in seafaring.

You should use the term starboard to indicate the right hand side.

It is the opposite of the portside.

It is a navigational term which reduces ambiguity while in the sea.

During the past, the navigation of small ships was done by a hand-operated rudder mechanism.

The handle was on the right side of the ship as a majority of the sailors were right-handed.

Why do Ships use ‘Starboard’ and ‘Portside’ and not ‘Left’ and ‘Right’?

This is because starboard and portside are unambiguous regardless of a mariners’ position.

You will thereby minimize the chances of confusion when communicating on which turn to take.

Ships in the past were having rudders on the center line and a steering oar controlled it.

Just like in the modern society, most sailors were right handed.

Therefore, since most sailors were using their right hand, steering oars were on the stern’s right side.

This lead to a majority of sailors were referring to the right side by the term steering side.

The name later changed to starboard.

Also, starboard combines two words: stéor and bord.

Stéor means steer while bord refers to the side of a ship or boat.

The left side of the ship got the name port.

This is since ships with starboards usually dock on ports on the opposing side of the star.

Port side and star board came about so that no interference came about during operations.

The other reason is that starboard and portside sound different.

Challenging conditions of the sea would make it hard for sailors to hear one another.

This is especially true since the left side was originally larboard.

Old English terminology for port side was sounding like backboard.

Sailors had their backs facing the left side of the ship while steering big ships.

Later on, backboard changed to ladder board.

Ladderbord is the loading side of these ships.

After that, ladder board was changed to larboard which happens to be quite confusing.

These terminologies makes sailors eliminate doubt when you compare it to right or left.

Is Portside the Default Loading Side for Cargo?

Yes, it is.

This is because the portside faced the port.

Hence making it easier for loading and offloading of cargo.

How do you Identify the Starboard and Portside of a Shipping Vessel?

You will notice the difference between starboard and portside as marked by the colors.

The portside is denoted by the color red.

The starboard side is marked by the color green.

Why is the Front of a Ship called Bow?

The origin of the word bow is similar to that of the bough of a tree.

Bough originates from a low German word that means shoulder.

The origin can be attributed to two theories.

First, the extreme front of the ship is known as head.

It is also the widest part of the ship behind the head meaning it would be followed by the shoulders or bough.

Secondly, wooden frames were used to construct wooden ships.

Also, the wooden frames had a prominent curve near the bow.

The ship builders were selecting timber pieces that would fit on the frames.

These pieces of timber came not from the tree trunk, but from the bough of the tree.

What Color are Port and Starboard Lights?

The colors for port side is marked by the color red.

You will find starboard lights are indicated with the color green.

What is the Back of a Ship Called?

The back of a ship or boat is called the stern.

However, when the ship is in backward motion it is referred to as moving astern.

If a person is moving towards the back of a ship, the person is going aft.

What Color are a Ship’s Stern and Bow Lights?

You will find a ship’s stern is color white and placed at an angle of 135 degrees.

You will note that the bow lights are bi-colored.

The portside lights are red.

The starboard lights shine green.

What is the Importance of Navigation Lights on Cargo Ships?

Navigation lights on ship

Navigation lights in ships

Other than being a requirement as stipulated in the COLREGs, there are other benefits to this.

The major purpose is to act as a guide to the direction of the ship.

Navigational lights also give the position of the ship.

Navigational lights act as indicators when overtaking, crossing or head on scenarios.

Also, the ships had white lights that were on the masthead and stern.

When you combine the red, green, and white light, it was easy to identify a ship during the night.

An example is when two sea vessels were approaching each other bow to bow.

The sailors would navigate the vessels to the starboard direction.

This means they would pass one another on the port side.

What is COLREGS?

COLREGs stand for International regulations for Preventing Collisions at Sea.

It came into effect on 15th July 1977 after adoption on 20t October 1972.

You will find them listed in the International Maritime Organization.

It is also referenced as “rules of the road”.

COLREGs are derived from the Convention on the international Regulations for Preventing Collision at Sea.

COLREGs govern the navigation of vessels at sea for ships and vessels to prevent collisions.

COLREGs is made of Six (6) sections.
It has 41 rules.

These six sections are as follows:

  • Section 1 – General;
  1. Rule 1: Applicable to all vessels on seas and all water bodies that connects to high seas.

Special rules made by maritime authority will be adhered to and take precedence.

  1. Rule 2: It ensures the masters, owners and the crew follow the rules.

Should the owners and or masters fail to follow protocol they will be held accountable.

  1. Rule 3: This part incorporates definitions.
  • Section 2 – Steering and Sailing;
  1. Rule 4: It applies to all conditions regarding visibility.
  2. Rule 5: Necessitates all vessels to be vigilant in terms of sight, sound, or other means applicable.

No vessel and or captain should make decision based on scanty information.

  1. Rule 6: It highlights safe speed of the vessels.

States that all vessels should take reasonable measures to avoid collision.

All vessels should check on the prevalent circumstances to avoid collisions.

  1. Rule 7: It will cover the risk of collision and no assumptions are valid when information is scanty.
  2. Rule 8: involves steps to take to avoid collisions.
  3. Rule 9: Vessels using narrow courses should be close to the outer side of the channel on the starboard side, etc.

Fishing vessels should not hinder the passage of other vessels in a narrow channel or fairway.

A vessel which of less than 20 meters in length should not hinder passage of another vessel.

  1. Rule 10: ships crossing traffic lanes be at right angles to the direction of the flow of traffic.
  2. Rule 11: This section will apply to vessels that are visible to one another.
  3. Rule 12: Highlights actions that two vessels approaching one another should take.
  4. Rule 13: It highlights overtaking requirements.

It stipulates that the overtaking vessel should keep way from the vessel being overtaken.

  1. Rule 14: highlights situations when vessels are head on.

All power driven vessels while headed for a collision should switch to starboard course.

  1. Rule 15: covers actions that the vessel which gives way should take.
  2. Rule 16: Contains rules which the vessel that gives way should apply.
  3. Rule 17: Highlights actions that stand-on vessels should take.
  4. Rule 18: Highlights responsibilities between various vessels.
  5. Rule 19: Ships should move at the right speed as per the current circumstances and visibility.

Each ship shall take into consideration the prevalent circumstances of restricted visibility.

  • Section 3– Lights and Shapes;
  1. Rule 20: mentions that rules pertaining to lights apply from sunrise to sunset.

This is applicable in all weather conditions.

  1. Rule 22: Gives definitions.
  2. Rule 23: Looks at lights that power-driven underway vessels should carry.
  3. Rule 24: Looks at lights which vessels that tow and push uses.
  4. Rule 25: Looks at the light necessities for sailing underway vessels and vessels using oars.
  5. Rule 26: This covers the light that fishing vessels use.
  6. Rule 27: This will cover vessels that have their movement restricted or with no command.
  7. Rule 28: It looks at vessels that have are affected by draught.
  8. Rule 29: This one covers light for pilot vessels.
  9. Rule 30: This will look at vessels that have docked.
  10. Rule 31: It looks at light for seaplanes.
  • Section 4 – Sound and Light signals;

Use of high intensity revolving lights should be avoided.

  1. Rule 32: Defines short and prolonged blasts, and whistles.
  2. Rule 33: Ships ≥ 12 meters should have a whistle and bell while those ≥ 100 meters must have an extra gong.
  3. Rule 34: It looks at maneuver and warning signals while using lights or whistles.
  4. Rule 35: Looks at sound signals in restricted visibility areas.
  5. Rule 36: Looks at signals that will attract attention.
  6. Rule 37: It looks at distress signals.
  • Section 5 – Exemptions; and
  1. Rule 38: ships built before this regulation can be excluded from some sound and light signals.
  • Section 6 – Verification of compliance with the provisions of the Convention
  1. Rule 39: it highlights definitions.
  2. Rule 40: contracting parties to apply code for implementation to execute their obligations in the current convention.

It also stipulates that every contractor shall be liable to audit.

  1. Rule 41: Contracting parties to undergo regular audits.

COLREGs has four (4) annexes.

The annexures cover:

  • International SOS codes.
  • Specification of shapes and lighting used.
  • Auditory signaling appliances
  • Signage of fishing ships within close range.

What are the COLREG Rules for International Shipping?

COSCO Shipping Lane

COSCO Shipping Lane

The COLREG rules are divided into (6) sections:

  • General

States that all vessels are in high seas are bound by the COLREG regulations.

Further states that the port side and starboard lights will only be on when underway.

Should a vessel be in motion it will have either one or two masthead lights dependent on its length.

A vessel should have day shapes and lights to indicate its nature and activity.

  • Steering and sailing.

States that all ships should always move at a speed considered safe.

The determinant factors of safe speed are:

Traffic density.


Wind speed and sea currents.

  • Lights and shapes.
  • Sound and light signals.
  • Compliance verification.

What is the Relationship between Starboard vs. Portside and Stowage Planning?

Stowage planning refers to allocation of space on a ship for cargo containers.

The planning is done in regards to discharge in different ports.

It is very important to have the proper storage of containers to avoid maritime disasters.

Stowage planning is done in consideration of several factors among them being:

  • Port of load.
  • Transhipment ports.
  • Port of discharge.
  • Ship size.
  • Number of containers.
  • Weight, size and type of containers.
  • Special care of items being shipped.

Calculation of storage is done by computerized software.

You will need to know the following when doing stowage planning:

  • Scheduled ports to be visited and the order.
  • Summarization of containers by weight, size and type.
  • The number of hazardous containers to be loaded at each port.
  • Number of containers already aboard.

What Kind of Goods is Best Loaded in Starboard?

Any goods can be loaded on starboard.

This is provided they adhere to load line restrictions.

The load lines put restrictions on the amount of load to be carried by a vessel.

However, it is advised that compatible load be loaded on the same side.

This is to avoid chemical reaction of items which are incompatible.

Caustic soda and acids should not be stored together because they will react.

The United States coast guard has released a cargo compatibility.

This checks if goods can be loaded together.

You should also check on the stability on each side of the vessel before loading.

This ensures the vessels does not break into two or sink while in the deep seas.

Various factor looked at when loading vessels are:

Port vs Starboard

Port vs starboard

  • Cleaning procedures.
  • Vapor return.
  • Toxicity
  • Heating requirements.
  • Boiling point.
  • Freezing point.
  • Pollution category.
  • Inhibitor requirement.
  • Maximum temperature.
  • Multi-port voyage sequence.
  • Limitation of load zone to port of destination.
  • Stress conditions and sheer force at sea.
  • Sequential distribution of multi-grade goods.
  • Voyage draft restrictions
  • Pre-wash requirements.
  • Trim of discharge and draining.
  • Valve segregation if applicable.
  • Permissible expansion of goods aboard.
  • Temperature of cargo load.
  • Venting capacity.
  • Electrostatic hazards.

Which side between Portside vs. Starboard is suitable for loading Hazardous Cargo?

Hazardous cargo can be loaded on either side.

This is provided they conform to the International Maritime Dangerous Goods code (IMDG).

The IMDG aims at preventing marine life and protection of the crew.

Hazardous cargo should conform to the density that is permissible.

The list of goods to be loaded need to meet an international Certificate of Fitness to transport hazardous goods.

It is also worthwhile noting that some items have temperature restrictions.

How do you Remember Port and Starboard?

Several ways to remember the port side and starboard are:

  • Associate the terms with the alphabet.
  • Buy a pair of socks indicated port side to be worn on the left foot and starboard on the right.
  • Check the letters, starboard has two Rs alluding to the right and port is associated with left.
  • Associate the number of letters with direction, port has four letters similar to left.
  • Learn a joke on the two navigational terms (Portside and starboard).
  • Know the etymology of the navigational terms.

How does Starboard vs. Portside help in safe navigation?

The terms reference the right and left sides without any confusion.

Any mariner will note the action to take when advised to turn to either side.

When two vessels are approaching a right of way is established using the navigational rules.

This takes into account if neither of the vessel is restricted in mobility.

When the starboard light is on, while approaching another vessel you can proceed moving forward.

If you observe portside light on approaching you need to give way.

What is Canting in relation to Starboard vs. Portside?

Canting refers to the effect of a vessel bow moving in a reverse direction.

This is the majorly caused when the ship is taken astern while approaching the jetty.

Does a Shipping Vessel’s Propeller Influence the Direction in which a Ship Navigates?

Yes, it does.

You will observe that for a propeller that is right handed, the stern swings to port.

The bow will move towards the starboard.

You will note that for a propeller that moves anti-clockwise, the stern moves to the starboard.

The bow moves to the port.
You will find propellers categorized into two (2):

  • Fixed pitch.
  • Controllable pitch.

Some of the notable propellers are:

  • Controllable pitch propeller.
  • Highly skewed propeller.
  • Self-pitching propeller.

Propellers influence the following movements:

  • Forward/Ahead movements.
  • Slowing down.
  • Stoppage

What is the Significance of Bow Thrusters in Ship Navigation?

Also commonly referred to us maneuvering thruster or stern thruster is a propulsion mechanism.

It is used to turn the vessel either starboard or portside without use of the ships propulsion mechanism.

You will note that it makes docking easier.

Bow thrusters are used to maneuver in the following scenarios:

  • Maneuvering in coastal waters.
  • Maneuvering in channels.
  • Entry in ports when experiencing harsh weather conditions.
  • Exiting ports in bad currents.

This is because docking can be achieved without moving the vessel forward.

Thrusters can either be mounted on either the stern or bow.

Bow thrusters have the following advantages:

  • Saves on cost as it reduces the need to stay at the port and use tugboats.
  • You will increase safety while berthing in adverse weather conditions.
  • You will be able to better maneuver the vessel at low speeds.

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