Here is a approximate map from Disney World and Orlando to South St Augustine Beach at Marineland park.
Remember, St Augustine City is about 30 minutes from the park. St Augustine city is the oldest city in the United States and there is plenty to see and do there. Also the facility is on the beach, so you can make it a beach day if you want. There is Free parking which is rare in Florida. 🙂
Please do not drive to St Augustine if you don’t have a reservation, you need to have a reservation to show up at the park. You can make your reservation online. Click the link below for more information on St Augustine Dolphin Swim.