it runs every 5.9 minutes. there is a small chance in cosmic terms that the shipyard will cycle and you will see the exact same ships. If you do, go buy a lottery ticket.
You know, yesterday, my little girls rotating musical toy that has all the different animals on it hit 'Cat' seven times in a row. If I win the lottery, 1st thing I'm doing is hiring someone to fix the SQL and server kit process. Then I'm taking everyone out for drinks. And then sticking J'inn with the bill.