Thanks for the pics.
I've now done 14 dives with my setup above, all in salt water. 7 were shore dives near home, I usually do 2-3 dives with 45-60 minutes between them, get a bite to eat (maybe 60 minutes), then get home and rinse everything and let the knives dry outside the sheath. 7 were boat dives, where I (poorly) rinse everything on the boat, then the knives have to wait in the sheath until I get home (1+ hours) to do a proper rinse and dry outside the sheath.
Unfortunately, the Benchmades (1 for me, 1 for the wifey) do rust. It's usually pretty minimal and can be wiped off with a paper towel. By minimal I mean a light red tinge on a small area, not a rust spot like in the pics above. This was true even after doing 3 shore dive where the knives were coated with mineral oil before hand. For the boat dives I never oiled the knives again, not even between diving days (ain't nobody got time for dat). I did get a couple tiny spots (spots a fraction of the size as the pic above) that required a lot more paper towel scrubbing. I can see how if I didn't get that off pretty quickly that it might turn into bigger spots like in Bison Ravi's pics. Also, like Bison Ravi has mentioned, a little rust happens where the blade goes into the rubber handle. I manage to wipe it pretty good, but it's pretty much impossible to clean that area perfectly.
I still like the knife, I think they are the perfect size and shape, the sheath and locking mechanism are great. The blade material seems to be very sharp, I just wish it didn't rust, like the Spyderco H1 steel. It's too bad the Spydercos look so weird to me. I could get over the rubber handle being difficult to clean if I knew the steel would never rust.
---------- Post added November 8th, 2015 at 01:55 AM ----------
These pics are after 14 dives. For the most part, there's no rust:
Along the handle is hard to clean:
More pics and higher resolution:
Benchmade 112 H2O rust - Album on Imgur
As you can see, the small amount of rust I was mostly able to wipe off. I wasn't able to clean as well where the blade goes into the rubber handle. There is some small amount of rust there, though some of that is rust that has been wiped off the blade and stuck to the handle. There is also a little bit of salt accumulated there. It's just really hard to clean that area!