Editing Invasion (section)

===By sea===
[[File:US Navy 030113-N-2972R-114 A Landing Craft Air Cushion (LCAC) Vehicle from Assault Craft Unit Four (ACU-4) transports Marine Assault Vehicles to Kearsarge.jpg|thumb|A [[Landing craft#Landing Craft Air Cushion (LCAC)|hovercraft]] carrying [[LAV 25|armored vehicles]] ashore during the [[2003 invasion of Iraq]]]]

Invasion by sea is the use of a body of water to facilitate the entry of armed forces into an area, often a landmass adjoining the body of water or an island. This is generally used either in conjunction with another method of invasion, and especially before the [[aviation history|invention of flight]], for cases in which there is no other method to enter the territory in question. Arguments in favor of this method usually consist of the ability to perform a surprise attack from sea, or that naval defenses of the area in question are inadequate to repel such an attack. However, the large amount of specialized equipment, such as [[amphibious vehicle]]s and the difficulty of establishing defenses—usually with a resulting high [[casualty (person)|casualty count]]—in exchange for a relatively small gain, are often used as arguments against such an invasion method. Underwater hazards and a lack of good cover are very common problems during invasions from the sea. At the [[Battle of Tarawa]], [[United States Marine Corps|Marine]] landing craft became hung up on a [[coral reef]] and were [[shell (projectile)|shelled]] from the beach. Other landers were sunk before they could reach the shore, and the [[tank]]s they were carrying were stranded in the water. Most of the few survivors of the first wave ended up pinned down on the beach.<ref>{{cite web | author=Ashton, Douglas F.| title=Tarawa: Testing Ground For The Amphibious Assault| year=1989 | url= http://www.globalsecurity.org/military/library/report/1989/ADF.htm| access-date=February 11, 2006}}</ref> The island was conquered but at a heavy cost, and the loss of life sparked mass protests from civilians in the United States.