The USS Potomac served as the President Franklin Delano Roosevelt’s “Floating White House” from 1936 until his death in 1945. How the USS Potomac came to reside in Oakland , California is a fascinating journey. Following a ten year stint as a Coast Guard patrol boat, the Potomac saw duty as a Caribbean ferry, Elvis Presley private yacht, and a stint as a drug smuggler that ultimately led to its sinking while tied up on Treasure Island.