We were there 45 minutes to half hour before opening last time. Guessing there were maybe 100 people ahead of us. Once the gate opened we went directly to the desk where you get tickets for the Arizona visit. We got tickets on the first launch to the memorial. That was in February.
On our first visit, we were likely the same distance back, but did not know the layout/procedure. We had purchased passes online for the Missouri, Ford Island, and Submarine tours. By the time we got in line for the Arizona launch we got tickets for later in the morning. Unfortunately, the launch wasn’t docking at the Memorial at that time because of technical problems at the dock at the Memorial. That was in October and busier that February at opening.