I don't really see ease of disassembly being a huge issue should one of the guns get wet. Both of the models you're considering are stainless steel and drying out the internals of the S&W shouldn't require much more than popping off the sideplate and perhaps giving the parts a very light coat of oil after they've dried.
I also like the provision for easy field stripping of the GP100. You may never need to field strip the revolver while on a camping trip, but it's nice to know that you can do it without removing small screws, springs and other little parts. You can use the rim of a cartridge to remove the grip screw of the GP and no tools are necessary other than that. If you have a screwdriver or multi-tool, fine but if you don't, it's still fine. The Ruger is designed to be more of a survivalist or military style revolver, to be serviceable in the extreme. I'm not going to remove the side plate from a S&W or Colt revolver while in the woods or in my canoe or at night by moonlight. Some others may, but I won't.
Webleymkv and TenRing, you both (and all others in this thread) make some great points. In considering the above two salient observations, I have to side with TenRing in the sense that I, too, don't plan on removing the sideplate "from a S&W or Colt revolver while in the woods or in my canoe or at night by moonlight. Some others may but I won't." But I sometimes have trouble getting bread out of a toaster...
I'm still considering all of the many options. Though I love the configurations of the Model 65 LadySmith and the 3" barreled Model 66, due to their relative scarcity, both of these revolvers are commanding pretty steep prices (when compared to their more prevalent counterparts) and I'm not a collector per se (now, my wife would ask: "Why do you have so many guns if you're not collecting them?"-a question for which I have no intelligent answer
). So, even though it comes real close to replicating the features, weight, size and general configuration of my Smith Model 686, due to the simpler field-stripping advantage and adjustable sights, I'm leaning toward the Ruger GP100 with the 4" barrel. Even at my age (68), I still do a lot of fishing from my canoe (my favorite area by far is the Boundary Waters in northern Minnesota) and getting my sidearm dunked is always a real possibility.
I appreciate all of those who have taken the time to offer their helpful suggestions and insights and look forward to further inputs. As sort of an aside, The TALO rendition of the GP100 is a very intriguing concept and I'm curious as to how much they are going for in terms of price. Also, can anyone give me an idea as to what is a good price for a 4" barreled Ruger GP 100? My local gun shop is asking $580.00 for one. Thanks again, all.