COLUMBIA - The state Hunley Commission took the first step toward building a museum for the Civil War-era submarine on Tuesday, more than a decade after it was first proposed.

The museum will be built on the Cooper River inside the old Navy Base, house the Confederate submarine, a collection of 19th century maritime artifacts and will cost at least $40 million.

On Tuesday, Hunley commissioners reached an agreement with the agency charged with redeveloping the base to create a Hunley museum authority, which will now be responsible for planning, financing and building the museum.

The Redevelopment Authority will take on several duties of the current Hunley Commission. The authority also will expand by four members, all of whom will be appointed by the Speaker of the House and the Senate Pro Tempore. Robert Ryan, executive director of the RDA, said a museum authority had to be formed because the commission, in its current configuration, could not build a museum.

"It puts us in the business of maybe building the museum because, of course, we don't have the funding to build the museum at the time," Ryan said. "We would hopefully have a site for it by the time it's conserved."

The Hunley Commission decided in 2004 to build the museum in North Charleston on the Navy Base, choosing the site over the city of Charleston and the town of Mount Pleasant. The city of North Charleston pledged $13 million to the museum.

Since then, little has happened because there is no need for a museum until the 150-year-old iron submarine is conserved and stabilized. That process will last at least another five to seven years.

Ryan said the museum authority will have to determine how long it'll take for a museum to be built, because there are so many factors involved.

"It's not going to be a really fast-paced thing," Ryan said. "It's going to be kind of methodical."

The Charleston Naval Complex Redevelopment Authority and the Hunley Commission signed a memorandum of understanding on Tuesday after meeting for 20 minutes, most of that time in executive session.

Randy Burbage, vice chairman of the Hunley Commission, said the members serving under the RDA will also serve on the museum authority. He added the long-term plan of the authority is to have the money to build a museum by the time the Hunley is ready and it's the museum authority's responsibility to find the money.

"We still don't have enough," said Burbage, adding the commission has some money, in addition to the cash North Charleston pledged.

The Hunley was built in Alabama and brought to Charleston in August 1863. The privately financed iron submarine was built to sink Union blockade ships, which would earn its owners $50,000 per ship in bounty. The sub, which carried a crew of eight men, sank twice in Charleston Harbor before it finally sank the USS Housatonic off Sullivan's Island on Feb. 17, 1864.

The Hunley disappeared an hour after that attack and was lost until 1995, when a dive team funded by adventure novelist Clive Cussler found the sub. It was raised in 2000. Since that time it has been at the Warren Lasch Conservation Center on the Navy base, where scientists have studied the sub and taken steps to preserve it.

Earlier this month, scientists immersed the sub in a chemical bath that will stabilize the hull, a critical step in the conservation process. The sub will likely be ready for display within the decade, which is why the Hunley needs a permanent home.

Cynthia Roldan can be reached at 708-5891.