The local acceleration of gravity depends on the other masses around you and your distance from them. So an object can only be truly weightless when it's infinitely far away from any other mass.
But an object appears to be weightless when it's in free fall, that is, when the only force acting on it is the force of gravity. In that situation, the sensation of 'weight' is impossible ... you can never feel that something is pressing against you, because everything else is also in free fall. So a scale on the floor can't exert force against your feet, the mattress on your bed can't exert force against your back, and your heart, liver, stomach and spleen can't exert force against your other guts. Nothing seems to have weight, because everything is falling with the same acceleration.
Remember that the total
velocity of the motion is the vector sum of the velocity you would have in
still water and the stream. Always place the vectors carefully to be able to
come up with an accurate sum vector.