Is it legal to fly under the Golden Gate Bridge? I recently had the opportunity to rent a plane and fly in the San Francisco Bay Area.  While flying in the HWD/OAK/SFO area is challenging enough, when I spoke of my adventures of flying above Alcatraz and the Golden Gate Bridge, some of my fellow pilots asked me if I flew UNDER the Golden Gate Bridge and voiced their desire to do so.  As a relatively new pilot (3 months), while flying is definitely an adventure for me, flying under a suspension bridge is pushing my minimum safety limits and just does not seem lawful. 

Others have told me that they have seen GA aircraft fly under the bridge. While I'm sure pilots have done it...I don't see how this can be legal.  According to sources on the internet the bridge is only suspended 270' above the bay.  It doesn't seem enough space to fly through legally.  

According to 91.119

Except for takeoff or landing, no person may operate an aircraft below the following altitudes;

a. Anywhere. An altitude allowing, if power unit fails, an emergency landing without undue hazard to persons or property on the ground.

c. Over other than congested areas.  An altitude of 500' feet above the surface, except over open water or sparsely populated areas. In those areas the aircraft may not be operated closer than 500' to any person, vessel, vehicle, or structure.

To me, 270' does not meet the legal requirements set in 91.119(c)  I don't consider the SF Bay or water under the bridge to be "open".

So, is it legal to fly under a suspension bridge like the Golden Gate or Verrazano-Narrows Bridges?
No, it would violate regulations unless it was to meet the needs of an emergency.

Don't forget the catch-all regulation about reckless operation; many regulations may be interpreted very subjectively, and I feel that it is safe to say that flying under the Golden Gate bridge would attract a lot of negative publicity and would ultimately be considered something that the pilot of a fixed-wing aircraft would certainly be reprimanded for.

That's not even considering whether the bridge is 500 feet high, boats that may or may not be passing under the bridge, and your question completely truncated the 91.119(b) that lists information for congested areas, which I am almost certain the Golden Gate bridge would be subjectively qualified as.