Evan Salant wrote:
I fly out of Linden (KLDJ) Airport, which is located under the floor
of Class B Airspace (Newark Airport's bravo airspace, shared with JFK
and LGA). The traffic pattern altitude at LInden is 800 feet and the
floor of the Class B airspace is also 800 feet.

My question is this: What is the airspace below the floor of this
Class B airspace ? Is it Class G ?

Would you be legal flying (daytime) simply "clear of clouds" ? Could
you fly with an 800 foot ceiling ?

The regulations on this are a little murky...I've heard some people
say Class E goes all the way to the ground below B but could never
find this in the FARs/AIM.

No, the regulations aren't murky. They state that a higher class of
airspace supercedes a lower class. If you check the sectional the
entire New York area is surrounded by Class E transition airspace.
(700-foot floor). That applies except where superceded by Class B or D
airspace. So, the airspace over KLDJ is Class G below 700 feet, agl.
There is a 100-foot layer of Class E below the Class B over the airport.