Cullen Bay has a range of restaurants many of them with views across the Marina to the upmarket boats and bayside houses of the well-to-do. 

The Boardwalk restaurant is popular with families and couples alike, and the food there is reasonably priced, and the seafood is good.  The salads and 'battered barra' (barramundi), and the prawns, are great. 

If you want to eat early the easiest way to reach Cullen Bay is by the relatively new number 14 bus (from the central bus station), timetables available from the Tourist Information site, but the last bus back is at 8.40 pm.  This is OK if you don't want to drive or take a taxi, and you can always complete the evening with a drink in one of the Mitchell Street bars, or one of the nightspots if you have the stamina.  But later evening dining is available at various Cullen Bay restaurants if you are not dependent on buses.