So...
If you've managed not to submerge your shotgun shells or your shotgun since you were about 15 years old they should be ok? Or if you keep them in a waterproof neoprene shell bag? (had some booze tonight, no offense intended)
BTW, I've killed more than one iPhone with salt water - yet I'm more careful with a 20 year old 870 express mag and shells to feed it...
If they are kept above the water line then you'll be fine
Why would someone use steel shot on dove, unless your shooting dove while duck hunting.
I don't know, maybe because there is 30% more pellets in a 1oz load of #7 steel vs #7 1/2 lead, they launch @ 1470 fps, they are $60 a case, provides a good tune up with your duck gun, and eventually you will be required to shoot them, it is just a matter of time.