While looking at the pictures from the Australian Nationals I noticed that the cleat and cheek block for the jib halyard are located at the center of the mast. On US boats the cleat and block are on the port side.

My question is this: Is it legal to move the cleat/block to the center of the mast from the port side in the US?

As far as I know moving the cleat/block is the only way to center the halyard while using the "aussie" halyard system.