In naval architecture

Naval architecture

Naval architecture is an engineering discipline dealing with the design, construction, maintenance and operation of marine vessels and structures. Naval architecture involves basic and applied research, design, development, design evaluation and calculations during all stages of the life of a...

, a flush deck refers to when the upper deck

Deck (ship)

A deck is a permanent covering over a compartment or a hull of a ship. On a boat or ship, the primary deck is the horizontal structure which forms the 'roof' for the hull, which both strengthens the hull and serves as the primary working surface...

 of a vessel extends unbroken from stem to stern

Stern

The stern is the rear or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite of the bow, the foremost part of a ship. Originally, the term only referred to the aft port section...

. There is no raised forecastle

Forecastle

Forecastle refers to the upper deck of a sailing ship forward of the foremast, or the forward part of a ship with the sailors' living quarters...

 or lowered quarterdeck. Ships of this type may be referred to as "flush deckers", although this is often taken as referring to a series of United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 destroyers originating from World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 and typified by the Wickes class

Wickes class destroyer

The Wickes-class destroyers were a group of 111 destroyers built by the United States Navy in 1917-1919. Along with the 6 preceding Caldwell class and 155 subsequent Clemson-class destroyers, they formed the "flush-deck" or "four-stack" class. Only a few were completed in time to serve in World...

. For aircraft carrier

Aircraft carrier

An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...

s it means that no "island" superstructure

Superstructure

A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships...

was fitted.