As secluded white sand beaches become a commodity more precious than oil, the Martha's Vineyard Land Bank this week announced significant expansions at two of its most stunning beachfront properties.

Moshup Beach in Aquinnah will grow by half again as much, and Wilfrid's Pond Preserve in Vineyard Haven will more than double in size.

"The land bank prizes beaches among its very many priorities, and expanding what already is conservation is a good accomplishment for everybody," said land bank executive director James Lengyel yesterday.

The property expansions are the result of a series of multiple transactions.

At Moshup Beach in Aquinnah the land bank now owns 1,155 linear feet of beach fronting the Atlantic Ocean, an increase of 50 per cent. The seller was Anne Weller Tagge; the purchase price was $393,000. The property had been owned by the late George Weller, Mrs. Tagge's father and a longtime summer resident of Moshup Trail. Mr. Weller's will granted a right to purchase the beach to Mrs. Tagge and her children, Katherine and Peter. The purchase went forward after Mrs. Tagge and her children had arranged with the land bank to conserve the beach immediately after they bought it.

The new piece of Moshup Beach will be placed under the existing management plan, which means it will be available for public use this summer.

The purchase at Wilfrid's Pond Preserve will increase the size of the property by 130 per cent, including 670 linear feet of beach and 5.6 acres. The addition took place in three separate property transactions.

In the first transaction, the land bank bought a .4-acre barrier beach lot from Edgar White and Robert White for $190,000. The beach lot fronts the Vineyard Sound and is backed by Wilfrid's Pond, a three-acre coastal pond. In the second transaction the land bank bought another .4-acre beach lot from Alexandra West. The purchase price was $280,000. The disparity in price between the two beach lots was explained in a land bank press release about the property purchase this week.

"The range of the two prices reflects the latter's greater marketability to prospective buyers; enjoying better access, it had a larger universe of possible purchasers and therefore a higher purchase price," the press release said.

In the third property transaction, the land bank bought one acre of shrubby upland southwest of Wilfrid's Pond from G. Kelvin White, who also sold the original property that created the preserve in 1995. Purchase price was $200,000. The purchase of the shrubland expands the land bank holdings around the pond, and it also resulted in a partial release of a deed restriction that was created by Mr. White at the time of the original sale. The restriction limited the trailhead at the preserve to nine parking spaces; there will now be room for 15 spaces.

An unusual pocket of Vineyard shoreline where the woodland literally runs right up to the dunes, the Wilfrid's Pond property had been owned by the White family since the Depression.

The purchase at Wilfrid's Pond will allow the land bank to manage the barrier beach itself for the first time, Mr. Lengyel said. "It's a significant change to now also own the land that is braced by the pond itself," he said.

Moshup Beach was first created in 1987 when the land bank bought 7.4 acres and 700 feet of beachfront in Aquinnah, then named Gay Head, from the family of the late George Long.

"It is to be used a public beach for all people," said Walter Delaney, a longtime Gay Head resident who was a member of the land bank commission at the time.

And now it is.

"At Moshup Beach people are always marveling at how beautiful it is and are going to be thrilled to enjoy even more than they have right now," Mr. Lengyel said yesterday.

Created by an act of the state legislature in 1984, the land bank buys public conservation land using money collected from a two per cent transfer fee on most real estate transactions.

Today the land bank owns 60 properties encompassing 2,280 acres, including 6.15 linear miles of great pond or ocean frontage.

Mr. Lengyel had an extra word of thanks for Ms. Tagge, who he said helped to steer an especially complicated transaction.

"The land bank wants to extend a particular thanks to Anne Weller Tagge, who sold this new length of Moshup Beach. It was a complicated legal situation and she persevered to be sure that the land bank obtained this beach. It was such hard labor on her part that we want to be sure that she knows that we are so grateful," he said.

He concluded:

"We are grateful to all of these sellers for having selected the land bank."