Answer the following question: Information: - An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An island in a river or a lake island may be called an eyot or ait, and a small island off the coast may be called a holm. A grouping of geographically or geologically related islands is called an archipelago, e.g. the Philippines. - Corinthia ("Korinthia") is one of the regional units of Greece. It is part of the region of Peloponnese. It is situated around the city of Corinth, in the north-eastern part of the Peloponnese peninsula. - Mean sea level (MSL) (abbreviated simply sea level) is an average level of the surface of one or more of Earth's oceans from which heights such as elevations may be measured. MSL is a type of vertical datuma standardised geodetic reference pointthat is used, for example, as a chart datum in cartography and marine navigation, or, in aviation, as the standard sea level at which atmospheric pressure is measured in order to calibrate altitude and, consequently, aircraft flight levels. A common and relatively straightforward mean sea-level standard is the midpoint between a mean low and mean high tide at a particular location. - The Gulf of Corinth or the Corinthian Gulf ("Korinthiaks Klpos") is a deep inlet of the Ionian Sea separating the Peloponnese from western mainland Greece. It is bounded in the east by the Isthmus of Corinth which includes the shipping-designed Corinth Canal and in the west by the Strait of Rion which widens into the shorter Gulf of Patras (part of the Ionian Sea) and of which the narrowest point is crossed since 2004 by the Rio-Antirio Bridge. The gulf is bordered by the large administrative divisions (prefectures): Aetolia-Acarnania and Phocis in the north, Boeotia in the northeast, Attica in the east, Corinthia in the southeast and south and Achaea in the southwest. The gulf is in tectonic movement comparable to movement in parts of Iceland and Turkey, growing by per year. - The Saronic Gulf (Greek: , "Saronikos kolpos") or Gulf of Aegina in Greece forms part of the Aegean Sea and defines the eastern side of the isthmus of Corinth. It is the eastern terminus of the Corinth Canal, which cuts across the isthmus. - The Corinth Canal ("Dhioryga tis Korinthou") is a canal that connects the Gulf of Corinth with the Saronic Gulf in the Aegean Sea. It cuts through the narrow Isthmus of Corinth and separates the Peloponnese from the Greek mainland, thus effectively making the former peninsula an island. The builders dug the canal through the Isthmus at sea level; no locks are employed. It is in length and only wide at its base, making it impassable for most modern ships. It now has little economic importance. - A municipality is usually a single urban administrative division having corporate status and powers of self-government or jurisdiction as granted by national and state laws, to which it is subordinate. It is to be distinguished from the county, which may encompass rural territory and/or numerous small communities such as towns, villages and hamlets. The term "municipality" may also mean the governing or ruling body of a given municipality. A municipality is a general-purpose administrative subdivision, as opposed to a special-purpose district. The term is derived from French "municipalite" and Latin "municipalis". - The Aegean Sea is an elongated embayment of the Mediterranean Sea located between the Greek and Anatolian peninsulas, i.e., between the mainlands of Greece and Turkey. In the north, it is connected to the Marmara Sea and Black Sea by the Dardanelles and Bosphorus. The Aegean Islands are within the sea and some bound it on its southern periphery, including Crete and Rhodes. - A submersible bridge is a type of movable bridge that lowers the bridge deck below the water level to permit waterborne traffic to use the waterway . This differs from a lift bridge or table bridge , which operate by raising the roadway . Two submersible bridges exist across the Corinth Canal , one at each end , in Isthmia and Corinth . They lower the centre span to 8 metres below water level when they give way to ships crossing the channel . The submersible bridge 's primary advantage over the similar lift bridge is that there is no structure above the shipping channel and thus no height limitation on ship traffic . This is particularly important for sailing vessels . Additionally , the lack of an above - deck structure is considered aesthetically pleasing , a similarity shared with the Chicago - style bascule bridge and the table bridge . However , the presence of the submerged bridge structure limits the draft of vessels in the waterway . The term submersible bridge is also sometimes applied to a non-movable bridge that is designed to withstand submersion and high currents when the water level rises . Such a bridge is more properly called a low water bridge . - Greece (' ), officially the Hellenic Republic (Greek: ' ), historically also known as Hellas ("" ), is a country in southeastern Europe. Greece's population is approximately 10.955 million as of 2015. Athens is the nation's capital and largest city, followed by Thessaloniki. - The Peloponnese or Peloponnesus ("Peloponnsos"), is a peninsula and geographic region in southern Greece. It is separated from the central part of the country by the Gulf of Corinth. During the late Middle Ages and the Ottoman era, the peninsula was known as the Morea, a name still in colloquial use in its demotic form (). - A moveable bridge, or movable bridge (common alternative spelling in American English), is a bridge that moves to allow passage (usually) for boats or barges. In American English, moveable bridge and drawbridge are synonymous, and the latter is the common term, but drawbridge can be limited to the narrower, historical definition used in some other forms of English, in which "drawbridge" refers only to a specific type of moveable bridge. - A table bridge is a moveable bridge in which the deck moves along the vertical axis. Hydraulic pillars under the bridge raise the bridge deck to allow barge traffic to pass beneath it. In contrast to a lift bridge, where the deck is pulled upwards along towers, the deck of a table bridge is pushed upwards by otherwise hidden pillars. The name originates from the fact that when open it resembles a table. - The Isthmus of Corinth is the narrow land bridge which connects the Peloponnese peninsula with the rest of the mainland of Greece, near the city of Corinth. The word "isthmus" comes from the Ancient Greek word for "neck" and refers to the narrowness of the land. The Isthmus was known in the ancient world as the landmark separating the Peloponnese from mainland Greece. In the first century CE the geographer Strabo noted a stele on the Isthmus of Corinth, which bore two inscriptions. One towards the East, i.e. towards Megara, reading: ""Here is not Peloponnesus, but Ionia"" and the one towards the West, i.e. towards the Peloponnese: ""Here is Peloponnesus, not Ionia""; Plutarch ascribed the erection of the stele to the Attic hero Theseus, on his way to Athens. - Canals and navigations are human-made channels for water conveyance (supply), or to service water transport vehicles. In the vernacular, both are referred to as 'canals', and in most cases, the engineered works will have a series of dams and locks that create areas of low speed current flow. These areas are referred to as" 'slack water levels'," often just called 'levels'. The main difference between them is that a navigation parallels a river and shares part of its waters, its drainage basin and leverages its resources by building dams and locks to increase and lengthen its long stretches of "deep enough" slack water levels while staying in its valley. In contrast, a canal cuts across a drainage divide atop a ridge (however humble), generally requiring an external water source above the highest elevation. Many canals have been built at elevations towering over valleys and others water ways crossing far below. Cities need a lot of fresh water and many canals with sources of water at a higher level can deliver water to a destination where there is a lack of water. The Roman Empire's Aqueducts were such water supply canals. - Corinth ("Korinthos") is a city and former municipality in Corinthia, Peloponnese, Greece. Since the 2011 local government reform it is part of the municipality of Corinth, of which it is the seat and a municipal unit. It is the capital of Corinthia. What is the relationship between 'submersible bridge' and 'moveable bridge'?
Answer:
subclass of