[Trevally.]

I have been thinking about how this could work.

When you are standing on the deck of a boat travelling forward, there is a lot of motion up and down as the boat pushes through a wave. (more so than side sway)

Now if I am used to standing on this deck (sea legs) I can sway with the movement of the boat. So my head is always parallel to the sea. If I had a stick in front of me that was free moving forward and back and fixed to deck, I could hold this against myself and continue my sway. So I become the stabilizer. If this was binos and could also pivot at the head - perhaps a steady view could be achieved.