Vintage Inboard Flatbottom Class
There were quite a few flatbottom classes that were running before and after W.W. ll that didn't make it to the 1960's.
Most of these were very regional and were only run in that part of the country.
The Racing Runabouts rules were determined by the price and cubic inches of the motor, and the motors were allowed only one carb venturi for every two cylinders, except the K class which was allowed superchargers.
The Service Runabouts rules went on cubic inches, length,  weight, and had to carry a crew of two people (driver & passenger).
This chart is from 1950.

   Racing Runabouts                                                  Service Runabouts

Classes that made it into 1960 are as follows:

• The B, E, and K Racing Runabouts rules stayed the same as shown in the chart above, except all three had to raise the engine prices allowed in the 1960's. The B racing runabouts ran up to the early 1970's. The E racing runabouts ran up to the late 1970's.
• The E & F Service Runabouts were the only Service Runabout classes to make it to the 1960's and 1970's. The only rule changes implemented were the cubic inches. The E's increased to 300 and the F's went up to 400.
• Z Racing Runabout - This was a flatbottom class that started in the late 1940's and was very similar to the hydro "T" class. They had to use Crosley or Aero-Jet motors of 44 cubic inch. They had to be a minimum of 9 feet long and run on gasoline. This class became extinct in the 1970's.
• SK Racing Runabout - Started in late 1950's, became Pro Stock in 1980.

B Racing Runabout 'Lil Bee 28-B     E Racing Runabout Naughty Lady 17-E     E Service Runabout Second Mortgage E-9       F Service Runabout Oh Mona M-3       Jersey Speed Skiff Class JS-66       Crackerbox Class Pile Driver 27-P