A marine vessel maneuvering supporting apparatus is used in a marine vessel which includes a propulsion system and a steering mechanism. The marine vessel maneuvering supporting apparatus includes an operational unit, operated by an operator, arranged to control movement and turning of a marine vessel, a target value computing unit having a plurality of computing modes and arranged to compute target values including a target propulsive force for the propulsion system and a target steering angle for the steering mechanism in accordance with an operational input from the operational unit, and a switching unit arranged to switch the computing modes of the target value computing unit.