Crevice Corrosion

[Brion Toss]

Hi there,
I think that "hanging in salt water for a spell" might qualify as oxygen-starved. It essentially defines a crevice corrosion environment. I don't know what alloys were in that carabiner, but it would be rare to find much of a potential difference. On the other hand, some grades of stainless are wonderfully vulnerable to crevice corrosion. And it is possible that you had live current juicing the process up.
Fair leads,
Brion