By Alexis Tereszcuk - Radar Entertainment Editor
The rock star and the bikini model hang together down under!
Both women are starring in the upcoming film Battleship and have been traveling the world promoting the new action flick.
Brooklyn wore her blonde tresses up in a pony tail and RiRi wore her long brown tresses down around her shoulders.
They gorgeous girls were also joined by their co-star Taylor Kitsch on the luxury yacht while they relaxed for the day.