In this particular case, standing on a tall bridge (with pedestrian walkway) provided a spectacular view.
Where to stand? I do ponder this question in advance whenever possible. But sometimes I don’t have detailed information in advance. If I recall correctly, on the day of this parade of sail, I did not know precisely where the ships would be sailing and realized the potential of the bridge only that morning when I arrived at the waterfront.
The question of where to stand sometimes involves the location of the sun. In the morning, sunlight will be coming from the east or southeast. Later in the day, it comes from west or southwest. That can be extremely important if my photographic expectations are front-light, back-light, or side-light.
A staged event, such as a parade of sail, will generally have a fixed start time that is outside of my control. In that case, perhaps the biggest question is whether to stand on the left bank or the right bank. For a recent Sail Boston event, I knew that the ships would be sailing into Boston Harbor through a channel between East Boston and South Boston; I had to choose one location, as travelling between the different locations was impractical.