The speed will increase, as there is acceleration, while the acceleration will remain constant, as gravity is constant.
A reference frame can be moving. To make sure that newtons laws still apply, the reference frame must not be accelerating.
The boat is moving at 22 m/s while the man is moving at 23.1 m/s.
That means the man, relative to the boat, is moving at 23.1-22 = 1.1 m/s.
v =d/t, so t = d/v --> t = 3/1.1 = 2.7 s