An amphibious assault is a military operation that involves deploying combat troops from ships at sea onto land, usually on a beach, despite enemy opposition (if the land is undefended, it's just an "amphibious landing"). The area where the troops land is referred to as a beachhead. The best known amphibious landing was the D-Day landing at Normandy in WWII, but there were many such actions in the Pacific theater of the war. Because amphibious assaults always involve naval forces, these assaults are usually supported by naval gunfire and aircraft.
A variation of this type of assault can also be done when an army needs to cross a large river. These operations are similar, with the landing site referred to as a bridgehead. While these assaults can involve naval units, they do not require them, as land units can be used to support these actions. In most cases, the goal is to establish a secure position to deploy or construct bridges to allow more units to cross the river en-mass. The goal of the defender is to prevent the deployment of the bridge or the establishment of the bridgehead. Due to the dangers associated with building and protecting the bridges, armies prefer to capture existing bridges.
"Amphibious" Landings in Science Fiction
- "We have to hold them until all transports are away. Prepare for ground assault!"
- —General Rieekan
In science fiction, this type of military operation is scaled up to the planetary level, with starships inserting troops into battle against ground forces defending a planet. In most science fiction, attackers use shuttles, dropships, or even starships capable of landing to deploy troops and equipment. Star Trek factions usually make use of transporters to insert troops during planetary assault operations, unless they are somehow blocked.