A bridge apparatus to transfer persons between a moving structure such as a vessel and a second structure such as an offshore installation, for example, to span gaps between work boats and fixed offshore installations such as wind turbines. The bridge comprises a platform supported by a line, the platform being moveable in a vertical direction by movement, of the line, wherein the line extends in a vertical direction from the platform to a capstan, and from the capstan to a counterweight. Thus the inboard end of the bridge can remain in generally the same vertical position in relation to the support structure of the vessel, moving with the vessel in the water, and the outboard end of the bridge apparatus can remain in generally the same vertical position relative to the wind turbine, and the relative vertical movement between the wind turbine and the vessel is compensated by the movement of the bridge, while the stepping on and stepping off points on the bridge remain generally still in relation to the vessel and the wind turbine.