Helped design them and similar variants..supplied the electronic control packages..supported builders trials when they were being built (late 80s)..member of design teams for JMAC and later SSC replacement designs that are just now going to production....
Just bragging..but I do know the LCAC pretty well. The weaknesses of the LCAC have been well known from almost the beginning; chief amongst those simply being that corrosion was rampant and maintenance a nightmare. During the SLEP, many of the hulls were scrapped because they were corroded beyond repair.
But...despite all that, the capabilities of the LCAC have always been remarkable. That capability comes with a very high maintenance cost..and probably always will. The new SSC replacement has a much simpler propulsion design and a LOT more composite components instead of the highly corrosive aluminum.
I actually owned and operated a hovercraft for a while..even being almost entirely of composite construction, I estimated that I had something like 50 hours of maintenance and repair time for every hour of flight time!! But it sure was fun....