Wouldn't something like the ShinMaywa US-2 be more useful and readily available?

If you accept the C-130 will be unsuitable for oceanic waters, the ramp could offer advantages for SOF in calmer littoral Ops for the insertion/extraction of assault craft and surface and sub-surface vehicles such as RIBs and AUV/UUVs, as down with the Chinook, but at far greater ranges.

It is meant for operations in the Pacific. No prizes for guessing why. During WW2 the Sunderland crews were eventually banned from conducting open ocean rescues as too many aircraft were damaged and destroyed doing it.

Orac, I would say the ramp will need a ramp addition inside to reach the water.

Inflatable slide,or roll-up one...

Its easy when you know how. They would just need semi submersible floats. The secret is not to stand up in the boat

Looks like this is not a new idea either.
https://jalopnik.com/a-c-130-hercule...e-t-1716610531
If you search YouTube for Hercules on Water (HOW) there is a discussion of a trial of an amphibious version of the C-130 which included a water ski to get airborne in higher sea states. It seems that it never got past the model stage.

Ekranoplans might be more viable. The Ukrainians would be happy to quote.

The Spruce Goose looks in good condition in a museum and could be made flyable. It would be more stealthy than a C130.

More on the 1968 amphibious C-130

https://photos.google.com/share/AF1Q...FFc1RjQkM0ekVn

Megan, rather reminiscent of the Albatross...

Now that you mention it treaders, yes, they had dozens of them parked wing tip to wing tip along the sea wall at Pensacola when we were training, always fancied the aircraft, whats not to like with two big radials.

I think that this idea is a ridiculous non-starter. Everyone knows that proper air forces are getting rid of C130.