You've seen some of the snorkel bonnets that they use on Land Rovers, I'm sure.
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Some are kinda tapered at the top, and look like a mushroom stuck up there on the tube, or, some look like ram air scoops. If you have the "ram air" type, you have to have a drain hole in the system to remove the water that condenses in the pipe from the rain. That reduces the maximum water level based upon the place you drill the hole in the pipe (usually the lowest point so the water will condense and drain rather than get sucked into the engine).
The enginaire type has a "centrifuge" of sorts consisting of an internal impeller that spins from the air moving over it as it goes into the engine. The faster the engine runs, the faster the impeller spins in it, and throws the water, dust, dirt out of the passages on the sides to provide cleaner air through your snorkel to the engine. There are many other types of "rain bonnets" out there that could fit on there. I was just letting you know about the one I found that makes my air cleaner last a
lot longer! Hope that will help!