The Smithsonian's National Museum of Natural History plans to announce today the largest renovation in its nearly 95-year history, creating Ocean Hall, an unusual hybrid of public display and research.

Ocean Hall will cost $60 million and cover 28,000 square feet -- 3,000 more than the successful makeover of the Hall of Mammals last year. It will bring together for the first time all 50 of the museum's marine scientists and government specialists in what's being called the Smithsonian Ocean Science Initiative.

"Oceans are going to be the most important topic for the public in the next decade. They will be the rainforest issue," says Robert Sullivan, the museum's associate director for public programs. "The hall will be a provocative starting point for those discussions. We are going to do what has been impossible for a natural history museum. We are going to do what is current."

This project will be the most visible example to date of the mandate given to the Smithsonian last year to improve its science operations. A panel studied science throughout the museum and recommended more financial and moral support of scientific work, which includes saving endangered species and studying ice formations. The report also advocated bringing some of the research in its seven laboratories and field camps to the museum exhibitions.

The panel's examination was prompted by attempts by Smithsonian Secretary Lawrence M. Small to close some of the scientific offices, such as the Conservation and Research Center in Front Royal, Va., a move Congress emphatically criticized and that has since been abandoned. The Natural History Museum has 186 scientists, the largest number of researchers at any museum in the world. Some are at the forefront of new discoveries, such as finding the origins of human remains in East Africa.

Ocean Hall is scheduled to open in 2008 on the first floor near the Rotunda. As visitors enter, they will hear the sounds of waves and sea gulls. Hanging from the ceiling will be a northern right whale, a 50-foot-long model detailed down to its calluses and the organisms that live on its skin. A vertical cutout of a beach will have magnified looks at the tiny organisms that live in the sand. An immersion theater will give visitors the feel of diving into the deep, borrowing the "safe terror" experience of amusement parks.

If that makes visitors too queasy, they can stand in a dark space and learn about bioluminescence and animals that glow in dark waters. Huge screens will show current video from the research vessels of the National Oceanic and Atmospheric Administration and the U.S. Navy. There will be a living coral reef, a captured giant squid and a special display for the coelacanth, a prehistoric fish that was thought to be extinct until one was found in 1938. The new displays will draw from the 33 million marine specimens in the museum's collection, including some preserved fish that date to 1838.

Plans also include establishing a Center for Ocean Science, a clearinghouse for marine research with a Web site that will serve as a portal to all Internet material about oceans. Cristian Samper, the Natural History Museum director and a biologist, wants the hall to have updates from current research. "I don't want the hall to be the same hall 20 years from now," he said.

Samper said the project was driven by both scientific and public questions about "the vastness of the oceans, their importance in the origin of life and their place in the livelihood of people." Oceans cover 71 percent of the Earth's surface and reach down for miles. They serve as a transportation system, a source of food and a destination for recreation. Nearly half the world's population lives within 93 miles of a coastline, according to the museum. In the United States, half the population lives on or near a coast, and more than 180 million people visit U.S. shores for an average of 10 days each year.

Oceans offer scientists numerous opportunities for research, from mineral deposits to pollution to mountain ranges. In recent decades, improved technology -- underwater robots, manned submersibles, satellite images -- has enabled explorations to unprecedented depths. Some of those projects have been enthusiastically documented on televised science programs, increasing public interest about ocean exploration and projects such as finding the Titanic. At the same time, a number of issues about the ocean's fragility are emerging. Beyond the El Nino Effect, scientists have been studying dwindling fish stock, rising waters and pollution.

Sen. Ernest Hollings (D-S.C.) joined Sens. Daniel Inouye (D-Hawaii), Ted Stevens (R-Alaska) and Judd Gregg (R-N.H.) in praising the new project. "It is high time to open a window on the oceans here in the heart of our nation's capital that will excite, educate and begin a voyage of discovery for the child in all of us," Hollings said in a statement.

So far, the oceans project has received $18 million from NOAA and $18.2 million from Congress. Samper said he was optimistic about raising money from the private sector. "There are so many people whose lives are touched by the ocean, who live along the oceans, who have a yacht or go fishing. We are going to try to use that," he said.

The Natural History Museum has 125 million items, some dating back millions of years, and holds the world's largest meteorite collection. It opened in 1910 with collections of the Smithsonian staff and other government scientists. For years these exhibitions were largely untouched, becoming themselves relics.

In the late 1990s, a massive renovation of the building, which is the size of 18 football fields, began. Each stage has drawn on substantial private contributions.

Kenneth E. Behring, a California real estate businessman, gave $20 million to redo the Hall of Mammals and the Rotunda, where the signature African elephant is displayed. Samuel Johnson, scion of the wax company, gave $1 million to install an Imax movie theater, food court and other attractions in a $42 million project, also supported by Discovery Communications. The Voices of Africa hall was renovated using Smithsonian funds. The gems hall, home of the 45-carat Hope Diamond, was redone with donations from philanthropist Janet Annenberg Hooker, who gave $6 million and a collection of yellow diamonds. Ronald Winston, an heir to the Harry Winston jewelry fortune, gave $1 million for the reinstallation of some of the best-known gems.

By the time the Ocean Hall renovation is completed, two-thirds of the building will have been redone.