Okay folks, full disclosure: I didn’t really go inside this park properly.
Before you hang me out to dry, I put an asterisk on this post because someday I will go back to San Francisco and I will actually do the entire museum tour.
We were waiting to do some kind of trolley tour thing with a very long line and I looked across the street and saw the sign for San Francisco Maritime NHP. The National Park logo told me there would be a stamp. I had just gotten off the Alcatraz tour with my fresh new stamp book and OH NO I just realized this should have been post #2 instead of 3. Mistakes abound. Anyway, I got overly eager and my family didn’t want to go any further than the entrance so I popped into the gift shop and got my stamp even though all I did was look at the ships from the dock.
We’re going to circle back to this one when I’ve actually visited. Now that I know what I’m doing, I don’t get stamps unless I’ve visited enough to get a feel for the entire site.

Source: nps.gov