A marine vessel (1, 54) comprising: a steering mechanism configured for steering the marine vessel (1, 54), the steering mechanism comprises a steering wheel, wherein the steering wheel comprises at least one shift switch (36, 37, 44, 45, 46) that is configured to cause the marine vessel (1, 54) to shift to at least one of a course holding mode for holding a course of the marine vessel (1, 54), a traveling direction maintaining mode for maintaining a traveling direction of the marine vessel (1, 54), a position maintaining mode for keeping the marine vessel (1, 54) staying at a predetermined position, a bow direction maintaining mode for maintaining a bow direction of the marine vessel (1, 54) in a predetermined direction, and a fixed point holding mode for keeping the marine vessel (1, 54) staying at the predetermined position and maintaining the bow direction of the marine vessel (1, 54) in the predetermined direction, characterised in that the steering wheel further comprises course adjusting switches (38, 39) configured for control of finely adjusting the course of the marine vessel (1, 54) navigating in the course holding mode or the traveling direction maintaining mode shifted by each of the shift switches (36, 37, 44, 45, 46), and the course adjusting switches are two course adjusting switches (38, 39) provided corresponding to a port and a starboard of the marine vessel (1, 54), respectively, the course adjusting switch for changing the course toward the starboard is located on a starboard side of the steering wheel when the marine vessel (1, 54) is in a straight moving state, the course adjusting switch for changing the course toward the port is located on a port side of the steering wheel when the marine vessel (1, 54) is in the straight moving state, and when the marine vessel operator rotates a wheel portion having an annular shape of the steering wheel by a predetermined amount or more in the course holding mode or the traveling direction maintaining mode, the course holding mode or the traveling direction maintaining mode is released. a steering mechanism configured for steering the marine vessel (1, 54), the steering mechanism comprises a steering wheel, wherein the steering wheel comprises at least one shift switch (36, 37, 44, 45, 46) that is configured to cause the marine vessel (1, 54) to shift to at least one of a course holding mode for holding a course of the marine vessel (1, 54), a traveling direction maintaining mode for maintaining a traveling direction of the marine vessel (1, 54), a position maintaining mode for keeping the marine vessel (1, 54) staying at a predetermined position, a bow direction maintaining mode for maintaining a bow direction of the marine vessel (1, 54) in a predetermined direction, and a fixed point holding mode for keeping the marine vessel (1, 54) staying at the predetermined position and maintaining the bow direction of the marine vessel (1, 54) in the predetermined direction, characterised in that the steering wheel further comprises course adjusting switches (38, 39) configured for control of finely adjusting the course of the marine vessel (1, 54) navigating in the course holding mode or the traveling direction maintaining mode shifted by each of the shift switches (36, 37, 44, 45, 46), and the course adjusting switches are two course adjusting switches (38, 39) provided corresponding to a port and a starboard of the marine vessel (1, 54), respectively, the course adjusting switch for changing the course toward the starboard is located on a starboard side of the steering wheel when the marine vessel (1, 54) is in a straight moving state, the course adjusting switch for changing the course toward the port is located on a port side of the steering wheel when the marine vessel (1, 54) is in the straight moving state, and when the marine vessel operator rotates a wheel portion having an annular shape of the steering wheel by a predetermined amount or more in the course holding mode or the traveling direction maintaining mode, the course holding mode or the traveling direction maintaining mode is released.