It's widely believed that there are 50 to 100 copies of Action Comics No. 1 floating around, which makes it exceedingly rare.

CNN: Rare comic of Superman debut fetches $1.5 million

By putting ships back into action with minimal transit time, floating dry docks are force preservers and multipliers.

CENTERFORSECURITYPOLICY: Center for Security Policy | Memo to the President: Your Legacy Must Be to Restore America��s Military