Half-Life: Deepening The Challenger mod
Underwater Research Facility, Abbreviated as U.R.F. Were part of the Black Mesa Research Facility, Located Far from the Base of Operation itself, The U.R.F. were tasked to Research Marine-Life and Developed an Undersea Technology. Its rumored that...
United States Black Mesa Mesa Research Facility Research Marine Undersea Technology Research Facility
Source: moddb.com