Details on the land fill between SF's original waterfront and the Embarcadero.greenspun.com : LUSENET : San Francisco History : One Thread
SF's original waterfront ran roughly along today's Montgomerty St. At some time in the early history of the city the current area between Montogmery and today's Embarcadero was filled. When was this work started, finished? When were the street numbers on the extended sections of the east-west streets finally established in their final locations?
-- Warren Deverel (email@example.com), June 10, 2004
During the Gold Rush of 1849 and 1850s there were no railroads, airplanes, or automobiles. The fastest mode of transportation to the first stop for the gold fields, San Francisco, was aboard a vessel. By the summer of 1850, over 500 vessels were recorded as being anchored in the vicinity of Yerba Buena Cove. After they had arrived, whole crews abandoned their ships, along with the passengers, to make their way up to the gold fields. Many of the vessels were eventually left to rot, others were eventually used for such purposes as storeships, saloons, hotels, jails, and some were sunk purposefully to secure water lot titles (property that was originally underwater). As wood was scarce at the time, due to the many fires that swept the city and the increasing need for building material, many of the vessels were also broken up for their timber as well as other parts such as the metal plating.
By 1851, the wharves had extended out into the cove and numerous buildings had been erected on piles near them. Over the next two decades, under various waterfront extension bills, Yerba Buena Cove was filled with sand from the downtown area. According to Bancroft, a local historian, "As late as Jan 1857 old hulks still obstructed the harbor while others had been overtaken by the bayward march of the city front and formed basements or cellars to tenements built on their decks. Even now  remains of the vessels are found under the filled foundations of houses." The cove was eventually enclosed by a seawall which was built from 1867 to 1869, and which followed roughly along the same path as The Embarcadero.
http://www.zpub.com/sf50/sf/hgshp1.htm (copy and paste to read more)
-- strange (firstname.lastname@example.org), June 13, 2004.
In 1977 or '78, the hull of the long-forgotten ship NIANTIC was uncovered alongside the Transamerica Pyramid. It was in the way of a new construction project, though, and its waterlogged timbers too far gone to be salvaged.
Archaeologists dug up what artifacts they could during a crazed rescue operation as the bulldozers waited nearby, and many items are now in the museum at the San Francisco Maritime National Historical Park. Some favorites include bottles of French champage found still intact in their original packing crates.
-- P.S. Perris (email@example.com), June 13, 2004.
The Niantic was uncovered in August 1872 after the demolition of the Hotel Niantic. She was 119? feet long with copper bottom plating. Twenty feet below the surface of Clay street the planks and ribs and stout keel were exposed. The Niantic was hauled to the corner of Clay and Sansome in 1849. In one of the great fires that swept the city, on May 4, 1851, it was burned down to the waterline. Eventually, the land was filled in around it and the hotel was built on top of the old hull. A brick building was built at the location which stood until the earthquake of 1906. The remains of the old hull were rediscovered in 1907, but were left in place. In May 1978, during the construction at < u>595 Sansome Street, the old hull was once again "rediscovered." During construction, most of the stern was destroyed, though some of the timbers were salvaged by the Maritime Museum. Approximately fifteen percent of the bow has been left undisturbed in an adjacent lot. Among the artifacts found were the ship's long windlass, two pistols, a rifle and derringer, 13 bottles of champagne, stoneware ink bottles, leather-bound books, bolts of fabric, cabin doors, hundred-year-old brass paper clips, copper sheeting, and nails.
From the notes on the zpub buried ships article:
Niantic Ñ a ship "now fast disappearing."  "...at the corner of Sansome and Clay streets, where her old hulk forms the foundation of the hotel of the same name." [57b] "That brings us down to the famous old Niantic, previously one of Goodhue's China ships out of New York, and was subsequently fitted out at Warren, Rhode Island, for a sperm Whaler. Captain Cleveland was her Master and his two sons were first and second officers. She turned up at Payta in 1849 and found a communication there from the American Consul at Panama, Mr. Nelson, stating that there was quite an emigration from Panama to San Francisco. Having a good supply on board he went there, and having secured 280 passengers, 20 of whom were in the cabin, she set sail from there on May 1st. Lost one passenger on the voyage, and first made Bodega Head and arrived in San Francisco at 11 PM, July 5th. The try works formerly used for trying out blubber was the kitchen. Among the steerage stewards were A. C. Bradford, afterward a District Judge in an adjacent county, and other was Harry Hoag. Of her passengers several have since become very rich. A. A. Hyatt owned one of the finest ranches in Solano county. Joe Douglas became a prominent financier and capitalist in Placerville, and a Mr. Orowell a prominent flour dealer. C. E. McDonald, whose is now located on Leidesdorff street, was also a passenger. There were also on board four negroes with their Southern owners. Every one knows where the bones of the old craft lay under the Niantic building, corner Clay and Sansome. George Ward had her there as a store-ship for some time. The old craft settled there, when foundations were being made through her for building purposes, one of her pump logs was driven down for a pile, and when well down it struck a stream of water, which formed an artesian well and supplied the inhabitants with water for several years..."  "I helped haul the ship Niantic in and sink her at the northwest corner of Clay and Sansome in the fall of '49. There is a house built over her now. Her bow is toward Montgomery. She was used as a hotel for a long time. A hollow pile was driven down through the stern below the salt-water line and about the best water in the town was pumped from that well..."; partly burned.  "Larkin [places her]...at NW corner of Sansome and Clay." [BA] "Workers excavating for the new Pacific Mutual Building at Clay and Sansome streets began finding hunks of old timber last week, but it wasn't until yesterday they were certain of what they had found - the hull of one of the original Gold Rush ships, the Niantic..."  "...[suggested historical area to include:] commencing at a point 100' W of corner of Clay and Sansome on sidewalk line of the N side of Clay, thence 50' due N, thence 90 degrees W, thence 90 degrees due S 50' to Sansome, thence 90 degrees due E 50' to point of beginning." 15 percent of vessel, bow, undisturbed in adjacent lot; 119? feet in length. 
http://www.zpub.com/sf50/sf/hgshp2.htm (copy and paste to view a fairly complete list of ships buried in San Francisco)
-- strange (firstname.lastname@example.org), June 14, 2004.