PurplePeople: This one appears to have run its course, and I am recycling the final location for a new hide.
For those who might care, the puzzle referred to the pendant numbers of US battleships (BB's) that were in commission at or near the time of the voyage of the Great White Fleet of 1907-8, which called at San Francisco during its round-the-world voyage. Each of the hypothetical squadrons in the letter contained one too many ships for proper coordinates, but subtracting the pendant number of each ship from the following ship's number would yield good coords.
The 'Bob' in the letter was Rear Admiral Robley Dungliston Evans, who commanded the Fleet on its way from the East Coast to San Francisco, and was relieved there due to ill health. 'George' was the hero of the Battle of Manila Bay, George Dewey, who held the rank of Admiral of the Navy at the time of the Great White Fleet. The starting coords for the cache are for a bed-and-breakfast that existed as a residence at the time of the Fleet. Evans' convalescence there is a complete fiction.