The case against Ferry Charters and Heritage Charters related to a tender issued by the Robben Island Museum for bidders to be listed on its database.
The Museum lodged a complaint with the Competition Commission in June 2016, implicating five companies in tender collusion.
The other companies were Thembekile, Silverbuckle and Nauticat Charters.
It was alleged that the companies met at a coffee shop in September 2015, where they discussed and agreed to increase the prices they would charge when responding to the tender.
In June 2018, the three companies entered into settlement agreements, with Thembekile paying a penalty of R350 000, Silverbuckle nearly R250 000 and Nauticat Charters more than R420 000.
The Tribunal found that Ferry Charters has been charging the same price for more than four years, and Heritage Charters had requested a ten percent increase prior to the tender, and dismissed the matter.