Ok, lots of stuff out there for rain and such, but what about rafting. Very likely the whole mess ends up in the drink. The cam will be in a housing but I need audio. Probably us a MD in a pelican with a sealed lead to ???

How would one deal with this?

Mike

Having been an avid kayaker, I know that 99% of the time in whitewater, all you will hear even with the best mics in the world, will be the static white noise of white water. You'll probably only get understandable audio in quiet float sections.
That being said, get the cheapest mics with tolerable sound quality, (don't want to risk damaging high dollar mics) put them in an unlubricated condom, and seal multiple times, along the cable. Small hose clamps should do well. Coming out of a pelican, seal it with silicone sealant (from an auto parts store) inside and out. You don't want ANY connections exposed. Test your system in a bathtub or pool, to work out any kinks. Be especially wary of where cables enter sealed sections. In testing, wiggle the cables here to make sure the seal is good under strain. Even with all this, it is not 100%
Option 2: Go wireless
You can put the reciever in with the MD, and no longer have any holes to seal, put the mic and transmitter in a zipoloc, in a drybag; also no holes to seal. drybags and the like will still transmit most sound through, experiment to avoid bag krinkling noises. Hope this helps, good luck, and stay dry.

Ah, I like the wireless in the drybag idea. That way you could pull the mic out quickly during floats.

I figured the actual whitewater parts would be too noisy, I am mostly looking for the guide/customer interaction during the quiet times whithout destroying equipment during the other moments.

Thanks for the idea, I think it will work perfectly!

Mike

Mike,
Another great accessory are little bands for hair called "Blax" that can be found at most better hair care stores. They stretch forever, but don't break. I carry a few in my wallet all the time for a number of uses, but the primary use thus far is putting a mic inside a dry condom. I usually put BB's in the reservior tip because I'm suspending mics in water, never rafted with one though. I'm sure you won't want BB's in your condoms if you are moving.
I'd look seriously at the AT 88 Pro wireless, simply because it sounds great, quite cheap, and for short distances is very, very good.

My suggestion is: Sound design!

When you film water with sync sound the water always sound as if it much larger and dramatic than the film shows. Taking separate sound in less dramatic water will give a more dynamic and suitable audio for your footage.

However you may need sync live track that you can use as a guide for your sound design.