Landing Craft Air Cushion (LCAC) has ushered in a dramatic innovation in modern amphibious warfare technology. There are numerous advantages of LCAC, including decreased risk to ships and personnel of being located, lower susceptibility to mines than other assault craft or vehicles etc.
The U.S. Navy uses LCAC to transport weapons systems, equipment, cargo and personnel of the assault elements of the Marine Air/Ground Task Force both from ship to shore and across the beach.
Assault Craft Unit (ACU) 5 describes in the following video their every day assignments and the most exiting parts of their job.
Naval Today Staff, January 3, 2014; Image: Wikimedia