The U.S. Marine Corps has revised its view of the future. Gone are the prospects of large (with hundreds or thousands of landing craft) amphibious operations that occurred in great numbers during World War II. The last operation of this type (Inchon) occurred in 1950, over 60 years ago. Now the marines expect to conduct raids, from ships up to 200 kilometers off shore. No amphibious armored vehicles could handle that, so landing tactics have to be changed. This resulted in major revisions to the specs for the new marine ACV (Amphibious Combat Vehicle) amphibious armored vehicle. The first ACVs (ACV 1.1) to arrive in 2019 will be wheeled armored vehicles that are not amphibious but would be moved to the beach by high speed landing craft (like the LCAC or Landing Craft Air Cushion). This version would carry 13 marines, three of them the vehicle crew. These will cost about $4 million each. After that will come the amphibious version (ACV 1.2) that will cost about $12 million each and only be able to travel about 20 kilometers from ship to shore. This version may also be able to carry more troops (up to twenty). The marines also want ACV 1.1 designed so that it can be upgraded to most of the 1.2 standard. All this will take at least a decade and many of the elderly AAV7s will have to stay in service until then. That will be made possible by some upgrades.
Upgrading the 1970s era AAV7 amphibious armored vehicles will prolong service life. In addition to better protection the elderly AAV7s will be refurbished so they can remain in use another decade or more. The marines never expected the AAV7s to last this long but several attempts to develop a replacement have come up short. Thus the need to extend the life of their thousand AAV7 amphibious armored vehicles. These entered service in the 1970s and are falling apart. Moreover, some two thirds of the AAV7s saw service in Iraq, where they got as much use in two months as they normally did in two years of peacetime operations. Some 400 AAV7s are already scheduled for refurbishing, which will begin in 2018 and finish in the early 2020s. Thus the AAV7s can still be used into the 2030s, or whenever a permanent replacement can be found.
The 29 ton AAV7s has a crew of four (driver, commander, gunner and rear crewman) and carries 25 combat ready marines as passengers. The vehicle is armed with a 40mm automatic grenade launcher and a 12.7mm machine-gun. Top land speed is 72 kilometers an hour on roads, 32 off road and 13 in water.
Back in 2011 the marines gave up on high-speed (sea skimming) amphibious assault vehicles. It then turned to a new ACV to replace the AAV7s. DARPA (the Defense Advanced Research Projects Agency) was called in to help design the new vehicle. This may sound either very innovative or very desperate, and in reality it was both. In part because the marines had spent three billion dollars in an unsuccessful attempt (the EFV or Expeditionary Fighting Vehicle) to design and develop a high-speed amphibious vehicle and partly because that failure made it clear that some original thinking was required. The $12 million ACV was the EFV without most of the expensive stuff that didn't work. In effect, the ACV was be a 21st century version of the AAV7, optimized to pass all its development tests and get into service as quickly as possible. DARPA quickly did its job but the resulting ACV was still more expensive ($12 million) than the shrinking marine budget could handle.
In retrospect, the marines could have just built the EFV without the high-speed capability but that was eventually considered technically and politically impractical. The problem remains that the technology simply does not yet exist yet to make the high-speed capability workable. The budget situation is grim, leaving the usually unstoppable Marine Corps running into an immovable object and improvising as best they can. The marines have asked the navy to develop a high speed amphibious craft (or “connector”) to get MPCs to shore quickly but the navy budget is also shrinking and probably unable to handle the cost of developing and building the connector.