A million-gallon saltwater reef in SeaWorld Parks & Entertainment's Discovery Cove theme park is on track for its scheduled opening in early June, company officials said Thursday.

Although an exact opening date still hasn't been set, "Grand Reef" is expected to debut sometime during the first two weeks of June, said Stewart Clark, the SeaWorld vice president in charge of Discovery Cove.

The 2.5-acre artificial reef is the first expansion at Discovery Cove since SeaWorld opened the limited-admission, boutique park in 2000. Planners say it will be filled with approximately 125 species of sea life, from fish and rays to sharks and urchins, among which guests will be able to walk, swim and snorkel.

The feature attraction will be an underwater walking tour dubbed "SeaVenture" in which guests will don 75-pound dive helmets — though they'll weigh only about 15 pounds once submerged — and follow a themed trail through schools of fish. The experience, which will be limited to guests age 10 or older and to groups of no more than six people at a time, will cost an extra $59 per person, on top of regular admission