Georgiapeach and KYT6DM's revelation that the final pit stop was on the USS Hornet in Alameda explains much. It certainly explains how they couldn't get close enough to see what was happening. Hopefully that will satisfy the conspiracy theorists.
That location blows me away. My Dad was in the US Navy for 22 years and most of my childhood was spent just a few miles away from Alameda. The final pit stop location was a Naval Base for many years, though it closed 15-20 years ago. I spent a lot of time on that base. We bought groceries at the commissary there. We went to movies there and used the swimming pool. I learned to swim there. We went to the pediatrician at the clinic on the base. I wish I could have been there to see TAR run the leg at a place with so many memories for me. I'll be looking forward to the finale with great interest.
Also, the Aircraft Carrier Hornet Foundation appears to be a private organization, so it must have been appealing to TAR as keeping it secret must have been much easier.