After sitting in the same spot for 10 years, the H.L. Hunley is finally ready to move.

Well, a few feet anyway.

This summer, the team at the Warren Lasch Conservation Center will take the 19th-century submarine out of the lift cradle that's held it since 2000 and set it upright for the first time since 1864.

It sounds pretty simple, but it's a significant step in the project -- and an ordeal that has taken nearly as long as it took to recover the sub from the ocean floor.

"We're almost done with the final plan," said Mike Drews, who manages the lab for Clemson University. "We sent it out for review to the (Hunley) Commission and the Navy. They looked at the preliminary plans and found nothing I would call red flags."

The rotation, as the scientists call it, will set into motion the final phase of the sub's rehabilitation -- and may answer lingering questions about its disappearance in the dark days of the Civil War. People have waited a long time for those answers but the crew at the Lasch lab has moved cautiously because, well, they don't want to drop it.

Since the sub was delivered to Warren Lasch in 2000, archaeologists and conservators have removed several pieces of the sub and emptied it of sediment, crew remains and other artifacts. That has potentially changed the strength of the sub and created new stress points. But computer models show that the plan to slowly inch the sub upright and to the floor of the tank it sits in will work flawlessly.

The planning for this has been more than simple engineering. Maria Jacobsen, senior archaeologist on the project, has been mapping the intricate pattern of sand, shells and sea life stuck to the sub's hull -- a chore that had to be finished before the sub could be moved. Because the Hunley was taken from the spot where it sank in 1864, that concretion holds the only record of the sub's 130-plus years on the ocean floor.

The concretion also serves as an extra level of strength and protection for the sub, which means that it's to the scientists' advantage to leave it on through the move. But once that's finished, all the concretion -- and evidence recorded in it -- will be removed.

"For the first time, we will be able to see the hull itself," Jacobsen said. "We don't know if there's hull damage, we don't know if there were leaks. The rotation is a monumental event."

If there are easy answers imprinted on the hull, they will likely be found in the next year.

The Hunley became the first successful combat submarine on Feb. 17, 1864, when it sank the USS Housatonic, a Union blockade ship. Shortly after the attack, the Hunley disappeared. No one knows why. This project is in part meant to prepare the sub for display in a museum, and in part to fill in the blanks in history.

Paul Mardikian, the senior conservator on the project, said it will take a year to completely remove all the concretion from the 40-foot sub.

"No one has ever seen the sub like that," Mardikian said.

In the meantime, the crew continues to restore the hundreds of artifacts found inside the Hunley. Mardikian just finished work on binoculars that belonged to the sub's captain, George E. Dixon. They look more like theater glasses than modern binoculars.

"They are Hunley sized," Mardikian notes. "Small submarine, small binoculars."

At the same time, Johanna Rivera, another conservator, is using a process developed at the lab to separate the crew's clothing from the sediment inside the sub (some of the more delicate artifacts were removed in what is called "block lifts," which simply means the scientists removed sections of the mud with the artifacts inside).

Much of the cloth has the consistency of wet toilet paper, but so far they have managed to restore part of Dixon's jacket and are still digging his suspenders and other items out of the sediment.

Slowly, the pieces of the Hunley's complex puzzle are coming together. And after the sub is set upright, and the concretion is removed, the scientists at the Warren Lasch Conservation Center hope that 147-year-old mystery gets a little less murky.