I agree a SAK is a good thing to have with you, i thought we were talking just knives not multi-tools. I would also always have my PCKS buck 110 with me for smaller precision cutting and skinning anyways, never only take one knife 
I agree that most stainless steels are not as tough as carbon, Some however are better or worse than others, for example D2 and BG42 are probably among the worst for toughness they chip/snap easy, but they also have very high wear resistance and edge holding, its always a balance. However a properly heat treated S30V blade held around 58-59RC is going to be almost as tough as most carbon steels and its stainless, which like i said is a big plus when you are around salt water.

The reason that things like machetes, axes and big chopping knives are traditionally made of carbon steels is for much increased toughness such steels provide over stainless steels. Stainless has a tendency to snap or suffer large chip outs when used for prying or chopping that most nonstainless blades would take in stride. It's true that such blades can be dulled by rust on their edges if not oiled in a humid envoirment, but this rust can be removed with the sharpener you carry.
I agree that most stainless steels are not as tough as carbon, Some however are better or worse than others, for example D2 and BG42 are probably among the worst for toughness they chip/snap easy, but they also have very high wear resistance and edge holding, its always a balance. However a properly heat treated S30V blade held around 58-59RC is going to be almost as tough as most carbon steels and its stainless, which like i said is a big plus when you are around salt water.