The U.S. Marine Corps is having nothing but trouble with it's amphibious armored vehicles (AAV). The current AAV, the AAV-7A1, was originally introduced in 1971, as a an interim design to replace the World War II era AAV-5 design. There was a radically new AAV design, the LVA, in the works. But the LVA was too advanced and the project was cancelled in 1979. The alternative was to upgrade the AAV-7's, and that was done, twice, in the late 1980s. This turned the AAV-7 into the AAV-7A1. But the additional weapons, armor and other equipment made the vehicle underpowered and slow. So the marines began developing the AAAV (advanced amphibious armored vehicle). This turned into a 37 ton armored vehicle that could move through the water at 50 kilometers an hour (more than three times the speed of the AAV-7A1.) Equipped with a 30mm cannon and 7.62mm machine-gun, the AAAV carried the same number of marines (20). But the 2,700 horsepower engine, needed to drive the water jets that provided the high water speed, meant that the AAAV burned twice as much fuel per kilometer over land as did the AAV-7A1. At 37 tons, the AAAV is ten tons heavier. The AAAV is a more complex beast, mainly because of the mechanism that allows for the high speed in the water. The AAAV carried less cargo than the vehicle it replaces. The AAAV is also more than three times as expensive, at over seven million dollars each.
The bad news is that, after all this time, the prototypes won't be available for testing and evaluation for another two years. The buying decision will be made in 2007, and by 2017 the marines expect to have purchased as many as a thousand of them. The marines currently have eleven "Amtrak Companies" (two of them in the reserves), each of which will have fifty AAAVs. The additional vehicles will be for training units and replacement for losses (via accidents or combat.) The marines could get by with 700-800 AAAVs, and may have to, as the cost per vehicle is still escalating and may reach $10 million each. The AAAV continues to have reliability problems, and it's complex, and expensive, high speed water jet system is the chief culprit.
If the AAAVs fail their testing and evaluation, the marines will be in big trouble. Many of the AAV-7A1s are suffering from corrosion, and would need major reconstruction to keep them serviceable. Replacing the AAV-7A1s with newly built vehicles would cost about $2.5 million each.