Marine Displacement | Calculations and Formulas

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Marine displacement is a critical concept in naval architecture and marine engineering. It refers to the volume of water that a ship or boat displaces when it is floating, which is equal to the weight of the vessel. Understanding and calculating marine displacement is essential for the design and operation of ships. This tutorial delves into the formulas and calculations associated with marine displacement, focusing on length, breadth, draft, and block coefficient. This concept is pertinent to fields such as Naval Architecture, Marine Engineering, and Ocean Engineering.

Marine Displacement Calculator
Marine Displacement Calculator Results (detailed calculations and formula below)
Displacement (D) =
Displacement (D) = l × b × d × c
D = × × ×
D =
Displacement Calculator Input Values
Length(l) = metres
Breadth (b) = metres
Draft (d) = metres
Block Coefficient (c) =

Example Formula

An in-depth tutorial on marine displacement and its associated calculations and formulas in engineering

The primary formula used to calculate the displacement of a ship is based on its physical dimensions and block coefficient. The block coefficient is a dimensionless number that describes how closely the shape of a ship resembles a rectangular block.

Displacement = Length × Breadth × Draft × Block Coefficient


  1. Length: is the length of the ship (in meters or feet).
  2. Breadth: is the breadth of the ship, often referred to as the beam (in meters or feet).
  3. Draft: is the vertical distance between the waterline and the bottom of the hull (in meters or feet).
  4. Block Coefficient: is a dimensionless value typically ranging between 0.6 and 0.85 for most ships.

Impact on Society

The development of marine displacement calculations has had a profound impact on society and technological advancements. By accurately calculating the displacement, engineers can design ships and marine vessels that are stable, efficient, and safe. This has enabled the construction of larger and more advanced ships, which have been central to global trade, defense, and exploration. Additionally, this knowledge is crucial in rescue operations, preventing maritime accidents and environmental disasters.

Real Life Application in Industry

Marine displacement calculations are widely used in the shipping industry. For example, in the design phase of cargo ships, engineers need to determine the displacement to ensure that the ship can carry the intended cargo without compromising stability or safety. Knowing the displacement is also essential for compliance with international maritime laws and regulations. Furthermore, in the oil industry, displacement calculations are crucial for designing oil tankers that can transport large volumes of crude oil across oceans efficiently.

Key Individuals in the Discipline

One of the key individuals in naval architecture and marine engineering is William Froude (1810-1879). He was an English engineer and naval architect who played a vital role in the development of ship design. Froude's work in hydrodynamics and his establishment of the first experimental fluid mechanics laboratory have been fundamental to understanding ship displacement and ship hull design.

Interesting Facts

  • The largest ships in the world have a displacement of over 650,000 tonnes. This is equivalent to the weight of around 5300 blue whales!
  • The conceptof marine displacement was crucial in World War II, where the design of different types of naval vessels, including submarines, battleships, and aircraft carriers, played a significant role in the outcome of naval battles.
  • The principles of displacement are not only applicable to ships but also to submersible vehicles and even to floating structures like oil rigs, playing a critical role in offshore engineering.


Understanding marine displacement and its associated calculations is vital for the design, construction, and operation of ships and marine vessels. The formulas for calculating displacement are fundamental tools in naval architecture and marine engineering. The advancements in this field, spearheaded by individuals like William Froude, have had a profound impact on global trade, maritime defense, and exploration. As maritime technology continues to advance, the principles of displacement will remain central to the safe and efficient design of marine vessels.