Or, since they make you wear raincoats and galoshes, you can keep the camera under the raincoat until you're far enough away from the mist/falls that you feel confident to take it out and grab a few pics. That's what I would do. [And if it happens to still get a little mist on it, just make sure you wipe it down afterwards.]
You'd be better off carting a manual film body aboard with you. I've put my Canons through a workout waterwise and they keep going, long after anything that would toast a modern camera.
YOU WILL GET SOAKED.. I mean more than your shower SOAKED... I mean category 5 on the wet side of the Hurricane soaked. I got some great pictures with my 1d-markII + 24-105L which has survived many wet adventures. At some point, the water was coming down SO hard that I pulled the camera underneath my poncho just in case.
You get less wet (relatively) if you head below deck and observe from the side... but there's no fun in that...