Courtesy of The Airstream
RV Association's FAQ page:

If I join a local Unit, what can I expect to gain?
The local Unit rallies are the backbone of the Club. These rallies are planned and executed by the members of the Unit. Most of these are weekend functions that
allow the working members the fullest use and enjoyment of their Airstream.
These weekends are usually planned short distances from home base which is another reason why there are so many units within the populous states.

Must I join a unit to become a member?
No! WBCCI has a Member at Large category which permits a person to enjoy
WBCCI membership privileges if Unit Membership does not fit their particular lifestyle

Just what will I do at unit rallies?
You name it . . . we do it . . . fashion, pet and hobby shows . . . games and contests of every sort . . . square, round and ballroom dancing . . . informational classes on RV safety and maintenance . . . and instruction sessions embracing most hobbies. Dinners, potlucks and eating out are part of these weekend agendas. Foods are sometimes prepared in unusual and different ways, as customs vary from one locale to another. Since these get-togethers are located in different parts, campgrounds and in different towns from time to time, it affords the opportunity to visit and tour local plants and businesses. One thing is sure, there is always something of interest for everyone at most all Unit rallies . . . but what's more important is that in meeting new people, you are going to make new friends and friendships will be formed that will last your lifetime.

How much are the membership dues?
Peanuts, when you think of what you get….what you’ve just read about.  Year unit dues range from $5.00 to $25.00 and the 2007-08 International dues are $55.00.  Your International dues cover the printing and postage to mail the Blue Beret and membership directory to your home.  Unit dues provide members with a unit newsletter and unit membership directory.