This is for you Tonk.
and all you Super Bowl Fans too.
Is there always this much security for the superbowl? Or do they think terrorists will blow it up?
Looks pretty standard to me (i.e. clearing passage with the Captain of the Port, maintaining a security zone, etc.). Bear in mind that Detroit is a major city with a certain demographic, located very close to an easily-accessible border crossing with Canada.
I had the pleasure of going out on my brother's small Coast Guard cutter for a "family cruise" during holiday fireworks in a major city. There was a flurry of radio messages between the Coast Guard and the state and local police boats, controlling all the traffic on the river and maintaining a security zone around the fireworks barge.
It was a real thrill - and when it was time for fireworks we (and the deck force) had the closest seats in the house, if you will. ;-) It was a fun time, but they do take this stuff seriously, and there was a plan in place in the event an unknown vessel disregarded the security zone.