 A future Marine expeditionary brigade operation would require 400 AAVs and 700 ACVs distributed through a series of naval connectors over a series of phases; due to the smaller vehicle manning capabilities of the ACV, fleet size would need to increase by one-quarter to one-third to move one company.About 400 AAVs will be upgraded with MRAP-level protection features including enhanced underbelly armor, seating, fueling systems, and fire protection, which will begin deliveries in 2019; AAVs will still be part of the initial wave, while ACVs arrive in subsequent waves.ACV 1.1 includes the four competitors of the previous Marine Personnel Carrier program and their entries, as well as a fifth unnamed company.