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.