SeaWorld San Diego will begin work in December on a multimillion-dollar renovation of its main gate area, which will be transformed into a reef-themed attraction.

SeaWorld spokesman David Koontz said operators of the Mission Bay marine-life park are not disclosing exact costs, but the investment will be “in the tens of millions of dollars.”

The renovation will create Explorer’s Reef, set to open in March 2014. Visitors will enter the park beneath an immense wave sculpture, giving the impression of entering an underwater world.

“The wave portal came to us as a very simple idea of going to the beach, wading into the shallows and diving into the water,” said SeaWorld creative director Brian Morrow in a statement. “We’ve all wondered what that would look like, and that’s what we’re creating with the new front gate.”

The park is replacing existing ticket booths with a beach-themed, concierge-style ticketing area, providing a single location to purchase admission and sign up for tours and special programs. SeaWorld San Diego is also doing away with the glass window between guests and ticket service representatives to create a more open and personal experience, operators said.

The interactive Explorer’s Reef will encompass more than three acres and include 24,000-gallon saltwater and freshwater touch pools; and nearly 5,000 fish, including 400 brown-banded and white-spotted bamboo sharks and 4,000 cleaner fish. Guests will also be able to interact with other creatures, including rays, skates and horseshoe crabs.

The attraction will also feature new stores and eateries. Officials said SeaWorld saw a 14 percent increase in attendance from 2010 to 2011, and is anticipating significant growth again in 2012.