A swimming aid comprises a floating body and a bottom viewer and may be used at a swimming pool or in the sea. The floating body is U-shaped in cross section and has a hood at the top thereof. The floating portion buoyantly supports the upper half of the swimmer's body in the water. The bottom viewer is made of a transparent material such as vinyl chloride resin and takes the form of a dome. The bottom viewer is installed on the top of the hood and provides a wide forward or underwater view of the swimmer. The swimmer when laying with his body on the bottom of the floating body can swim without great resistance while looking forward or downwardly underwater through the bottom viewer.
