Could an Iowa-class battleship serve as an Amazon gunboat?

Could an Iowa-class battleship operate as a gunboat on the lower Amazon?

Only theoretically; a river gunboat must be able to maneuver within the navigable channel, and the Amazon's shifting mudflats, sandbanks, and depth limits make an Iowa-class ship an unsuitable choice.

The answer distinguishes the apparent width of a river from the part that is both deep and wide enough for a large warship to turn safely. A vessel that must reverse out of confined water is a poor river-gunboat design regardless of its firepower. The lower Amazon also contains moving mudflats and sandbanks, so a charted route is not a permanently clear maneuvering area. Draft, turning room, and changing riverbeds govern riverine ship design.