St. Clement's Island, Maryland's equivalent of Plymouth Rock where the state's first settlers landed in 1634, is washing away.

The winter storms are the things that really hurt, the violent whirlings of wind and rain that carve off large chunks from the shoreline of the island and deposit them in the Potomac. The gentle tidal swells do the island no good either.

While the situation has improved in the past 10 years, only about 60 acres of the original 400 remain above water.

Despite 15 years' worth of efforts to put some sort of barrier between the island and the water, the situation is still bad enough that several delegates, including House Speaker John Hanson Briscoe, are asking their colleagues to approve a supplemental budget appropriation of nearly $1 million to help preserve the island.

"This has tremendous significance to this state," Briscoe said yesterday. "The island, without protection, could eventually be totally gone It's something you can't put a price tag on," added the St. Mary's County Democrat, whose district includes St. Clement's Island.

At the moment, the island is home only to several hundred rabbits, a few muskrats, some herons and gulls and a few osprey. But every September, several thousand people ride out to the grassy island and gather around a large white cross to commemorate the original landing of Father Andrew White's naval vessel the Ark and the Dove.

During the past 15 years, buffers of piled-up stones, called riprap, have been constructed along much of the island's shoreline, particularly those sections facing the mouth of the Potomac and the Chesapeake Bay, where the worst of the storms come from.

But "even now, some of the heavy storms we've had have gone over some of those barriers," said James Weems, of the state Department of Natural Resources.

On the northernmost tip of the porkchop-shaped, island, however, there are no bufffers. At the moment, one area of shoreline is only 100 feet from a central pond and marshy area that reaches all the way across the island -- and the erosion at that point is eating away at the shore at a rate of four feet a year.

In 15 or 20 years the island may be cut in two.

"Historically, there's been a rapid rate of erosion on all the shortline -- a critical rate." explained Leonard M. Larese-Casanova, head of the Shore Erosion Division of the Natural Resources Department.

"Two thirds of the island has been somewhat protected," he added. "But there are still major problems." A study prepared by Larese-Casanova's department estimates that about $960,000 will be needed to repair the earlier riprap barriers and to build new ones.

Technically, the island belongs to the United States Navy, but that department has given the state of Maryland a 99-year lease on the island, and the state is responsible for managing it.

Earlier, before the Navy acquired the island as a target site early this century, it had belonged to the family of suspended Gov. Marvin Mandel's wife, Jeanne, and many people still call it Blackistone Island, after her ancestors.

"There's nobody living there now and there's not been anyone there as long as I remember it," said Weems, but there was 25 or 30 houses there once, and a lighthouse that the navy tore down."

"Some of the rates of erosion I've seen quoted are as high as 10 feet a year on the southwest, south and southeast sides," said Larese-Casanova. "In bad storm years." But he added, with the help of the protective barriers. "It'll take a while for the thing to disappear. We haven't lost very much at all in the past few years."