Matt wrote:
That is my understanding as well. But the last instruction I received from
the approach controller before being handed to the tower was to descend at
my discretion. I decided to turn onto final without ever being specifically
told to do so by the approach controller or the tower controller.

I would have asked. You don't want to play around in Class B.

When flying (san francisco) Bay tours, sometimes SFO tour routes you
over midfield when a heavy is departing runway 28. Sometimes they just
say 'cross over midfield' or give a heading without a typical IFR "turn
right heading XXX *to intercept Victor YYY." I know that after I cross
midfield they'll tell me to intercept the 101 freeway but I always ask
just in case there are 2 heavies taking off." Always ask because you
could be in for a rude awakening.

Gerald