[Iron Budokan]

Perhaps some binoc swaying would be acceptable but certainly not as much as, say, the periscope does. When you're holding binocs your muscular control can continually make minute adjustments to keep the image steady. ...Or steadier than would appear through a periscope which is affixed to the boat.

With that in mind the image in the UZO should sway just as much as the image in the periscope since it's fixed to the boat as well and not subject to as many minute corrective adjustments as hand held binoculars.