What Exactly Did The Titan Submarine Passengers Pioneer?

Exploration tourists want you to call the Titanic sub passengers "pioneers." Pioneers of what, exactly?

Related Keywords

,Roald Amundsen ,James Cameron ,Don Walsh ,Yuri Gagarin ,Explorer Club ,Type Of Guy ,Challenger Deep ,Wall Street Journal ,Richard Garriot De Cayeux ,Submersible ,Aaron Walsh ,Titan ,Wreck Of The Titanic ,Oceangate ,Titan Submersible Implosion ,Guy ,Alopnik ,