Abstract: A swim-in-place pool has an inlet opening to the swimming area, which is comparable in width and height to the space that would be occupied by a swimmer's body. Water is driven through the inlet opening at a velocity which is substantially constant throughout the cross-sectional area of the opening.The illustrated apparatus includes a housing providing an annular cavity within which a circular water advancing means is revolvably disposed. The swimming space lies essentially along a diameter of the annular cavity. The inlet opening is provided at one end of the swimming space for receiving water from the annular cavity, and an outlet opening is provided at the other end to return water to the annular cavity.