It's easy to travel to Ocean Park by car. Just drive through the Aberdeen Tunnel from its Wan Chai Entrance via the Canal Road - Wong Nai Chung Road Overpass. The tunnel fee is HK$5 (one-way).
After going through the tunnel, you'll be on Wong Chuk Hang Road. Turn left into Ocean Park Road and left again at the Ocean Park Road roundabout to reach the Main Entrance.
It is very convenient to take public transportation to the park. To support the environment, please consider using public transportation.