Next to the Great Siberian Railway, the Deep Sea Divers, was a smaller concession that  utilized  real divers. Wearing  huge metal suits inside a large aquarium adorned with propped  and artistry,  they appeared to be treasure hunters searching,  for sunken wealth among dangerous sharks and sea (artificial).  
Creatures. Edgar Cleary, a diver at the show made 4 dollars  a  day.  This included cutting his air hose and  fighting his way  back to the surface. Cleary was said to be in the water close to 7 hours  a day. Divers employed by the United States Diving Company explained methods of recovering and raising sunken ships. Divers working under water in a glass tank in full view of the audience appeared to search for hidden treasure.  

A barker with sailors and a helmeted diver would 'help' convince  visitors to enter the attraction, of course for a fee.
Exhibit Statictics:

Building cost:   6,000 dollars
Price of Admission-  15 cents, children 10 cents
Exhibition Profit-   13,765 dollars
Lee  Gaskins'   AT THE FAIR  The 1904 St. Louis World's   Fair 
                   Web  Design and Art/Illustration   copyrighted  2008
Fairgoers passing the attraction