Strap on your flippers and your oxygen tank — the new ocean exhibit at the Smithsonian’s National Museum of Natural History takes visitors farther underwater than they have ever been before.

From the 45-foot model of a North Atlantic right whale suspended overhead to underwater scenes moving across eight

high-definition video screens around the room, Sant Ocean Hall makes visitors feel like they are actually exploring the deep sea.

“There are things in there that you haven’t seen before, things that you can’t even imagine living in the ocean,” said Elizabeth Musteen, project manager for Sant Ocean Hall. “We really got to pull the best of the best.”

At 3,000 square feet, Sant Ocean Hall is the largest single exhibition space in the museum and represents the most extensive renovation since the museum opened in 1910. Although the hall displays an impressive collection of 674 marine specimens, the exhibition also uses high-definition video and computer technology to introduce visitors to more complex aspects of the ocean.

“We hope that visitors come away with the fact that the ocean is a global system, essential to all life, including yours,” Musteen said. “What you do here can affect things around the world that you don’t even know about.”

To illustrate the ocean’s importance in a global context, the “Science on a Sphere” exhibit literally projects visuals based on satellite date onto a six-foot wide globe. The globe continuously rotates 360 degrees, allowing visitors to view the images from all angles from the perspective of an astronaut hovering 22,000 miles above the earth. The visuals illustrate plate tectonics, temperature, currents and weather prediction models, highlighting the ocean’s constant motion and interaction with land.

For the museum’s younger visitors, however, Musteen said the models and preservations of marine specimens tend to be more popular.

Suspended above visitors’ heads, a 2,300-pound model of a North Atlantic right whale is the exact replica of an actual female whale that lives in the wild today. Nicknamed Phoenix, the whale has been tracked by scientists throughout her lifetime and is one of less than 400 North Atlantic right whales that survive today.

Underneath Phoenix, a long, horizontal glass display contains another popular exhibit among younger visitors — a 24-foot giant squid.

Coated in 1,800 gallons of a special liquid preservative, the female squid was originally 36 feet long but shrunk after it was soaked in the preservative. Fisherman found the female and a nine-foot male squid also on display about 1,300 feet below the surface of the Atlantic coast of Spain in 2005. The United States Air Force transported both squids to Washington, D.C., for the exhibition, making Ocean Hall the only place in the world ever to display a male and female giant squid in the same exhibit.

Although adult visitors also enjoy the squid, many spend their time exploring short films, ancient fossils and detailed diagrams that younger visitors overlook.

“Of course the giant squid is a highlight — who knew they were that long? — but I really like the deep ocean exhibit,” visitor Cathy Mack said.

“The squid is pretty cool, but the thermal vents at the bottom of the ocean were amazing,” visitor David Noble said, referring to a video exhibit that shows how volcanic activity along underwater plate boundaries creates thermal vents.

Alice McCauley, who was visiting the exhibition from California, said the cultural exhibit was her favorite part. The exhibit features a 26-foot Native American canoe from the Tlingit Nation commissioned especially for Ocean Hall to show how different cultures interact with the ocean and use it to survive.

Yet the most puzzling exhibit in Ocean Hall features two preserved coelacanths, enormous prehistoric fish thought to have gone extinct 65 million years ago until fisherman caught one off the South African coast in 1938. The adult coelacanth and the fish pup attract the attention of young and old alike.

“What is that, Mommy?” asked one boy, pointing to the giant fish. “That’s a col … col … That’s something Mommy can’t even pronounce,” his mother responded, staring at the fish open-mouthed.

Visitors of all ages also pile into Ocean Hall Theater to watch a 13-minute film following scientists on a two-mile submersible ride to the bottom of the ocean. The film features gorgeous footage of deep-sea creatures that most visitors have never seen before, including bioluminescent and transparent organisms.

Other exhibition highlights include a live, 1,500-gallon Indo-Pacific coral reef aquarium and two “Ocean Today” touch-screen kiosks that provide visitors with the latest ocean news.

Attracting about 41,000 visitors on opening day on Saturday, Sant Ocean Hall has been in the works since the museum took down its old marine exhibit to install Mammal Hall in 2003. Washington philanthropists Victoria and Roger Sant donated $15 million to endow the hall and related programs, while the remainder of the hall’s $49 million budget came from a $21 million federal appropriation and donations from businesses and individuals.

Featuring the largest marine collection in the world, Sant Ocean Hall is unique in its focus on a global view of the ocean. The exhibition emphasizes the unknown and unexplored elements of the ocean instead of what humans already know.

“They really took man out of it,” visitor Anita Kasch said.

“It is a system hall,” Musteen said. “It deals with every department in the museum … This is a new trend for us.”

The National Museum of Natural History is located on the National Mall at 10th Street and Constitution Avenue Northwest. Admission is free, and the museum is open daily from 10 a.m. to 5:30 p.m. For more information, visit mnh.si.edu.