float bridge

A float bridge is a bridge without major structural supports, which simply floats on the medium it crosses (normally a body of water), and is tethered or anchored to its ends and often to a series of midpoints.

Buoyancy supports the crossing instead of a succession of major supports founded beneath the span. Anchors or tethers keep the floating structure in position.

Connections can be made at the ends and at intermediate points. These restrain movement without changing the floating means of support.