For our sleuths and esteemed mapmaker:
Battle Creek NV is a ghost town, as was mentioned. It's north of I-80.
http://www.ghosttowns.com/states/nv/battlecreek.htm
Battle Creek Mines are south of I-80. Does John have an interest in mines or ghost towns? This seems out of sync with the water searches.
http://www.ghosttowns.com/states/nv/battlecreek.htm
Martinez is along the Suisun Bay which connects to the SF Bay. Does John have any history or real estate holdings there (past or present)?
https://en.m.wikipedia.org/wiki/Martinez,_California
The Tidal Canal area (we used to call it the Estuary) he searched is near the Fruitvale Bridge. It is between the High Street and Park Street bridges. Either the Fruitvale or the Park Street bridges could be the most direct route from his house to Oakland (but not downtown Oakland). I would expect that John could walk there from his house.
https://www.acgov.org/pwa/about/maintenance/bridges/bridge_high.htm
Westline Dr. along Robert Crown Memorial State Beach would connect him with Shoreline Dr. along the SF Bay in Alameda.
http://www.parks.ca.gov/?page_id=526
I would suggest privately finding out who the resident of the Ripley Ave house is and seeing if anyone in the family knows who it is. Consider contacting them. Could this be real estate he has owned? Could he have determined it was vacant and thought of going there for some purpose?
So he searched areas near three different bodies of water, but we know he actually went out to the Pacific Ocean, after searching those locations on the morning he disappeared. Were there any tide searches?
Did he visit any of the locations in the Bay Area between 2/2 and 2/8 and decide they weren't suitable for whatever he had in mind?
I don't think he was leaving clues, as they weren't easily visible searches. The SF searches were found quickly and he actually went there.