Refers to an act in which the performer moves around the 'bar' performing a wide range of movements
(foremost, steering & mainsail trimming)
while the 'bar' itself stays mostly in place.
The difficulty is in making every move look effortless.
It is like dance, where most people of a reasonable strength
can get onto the bar for the first time and do the tricks, an experienced artist will do them with much more grace and style.

disclaimer: photos of the performer being catapulted into the drink upon flipping the 'bar'
have been omitted to preserve the 51 yr old artist's insurance qualification ...