On: 'Underwater bicycle' propels swimmers forward at s...

[cassianoleal]

Especially clipping your feet to a bouyant device!

[xhkkffbf → cassianoleal]

Better than clipping them to a non-buoyant device. Or worse, the classic cement overshoes.

[cassianoleal → xhkkffbf]

If it's non-buoyant and not very heavy, it's easier to control and stay afloat than if it pushes your feet upwards to the surface.