-I came across two articles discussing a US Special Operations Command (SOCOM) proposal to make the C-130 amphibious. Air Force Wants to Move Fast on Boat Plane for Special Operators and AFSOC aims to fly an MC-130J Commando II Amphibious Capability prototype in 17 months - The Aviation Geek Club
-The diagrams appear to show a C-130 on floats.
-My last duty assignment was at SOCOM and in the J-3 /SO-OP office there was a beautiful model, maybe 1:48 scale, of a C-130 flying boat. The model was wood, I think, and not really detailed but there was no sign of conventional landing gear so I guess the wee beastie was a pure flying boat vice amphibian. Unfortunately 99% of SOCOM is classified as a SCIF meaning there was no chance of getting a photo and the Public Affairs office had no idea what I was talking about.
Earlier thread is here. I linked an article from Military.com there about the decisionin' process in that thread.
It looks like a good idea, given the challenges China is posing with island-building in the South China Sea, as well as the accessibility to Yemen and East Africa to terrorist targets. Perhaps the Eastern Med as well? As an insertion/extraction means for long-range missions, it looks like a good idea, faster than heloes and more capacity too.
Apparently, this design features removable pontoons, so that it doesn't lose conventional ability beyond the mission at hand. Me likey.
I posted info & illustrations from two earlier (1964-73 & 1996-97) proposals for water-going C-130s in the Herculese Black Cat thread that Thumpalumpacus linked in his post.