Trojan non-lubricated condoms work very, very well for keeping mics dry. Doing that right now in Hawaii on a small shoot. Stretch em' tight, use Blaxx hair bands to hold it on, with a tiny bit of Vaseline to assure there is no leakage at the cable side. This works for the wireless as well, if you need to waterproof it. Just be sure the condom doesn't make the transmitter antenna coil or lie next to the mic cable. Carefully lay the antenna so it is to the side of the transmitter and you won't kill your distance too much.

Yes, it is possible to do that but as it requires accurate knowledge of the difference between the channels in both amplitude and phase it would probably be necessary to separate into several bands in the frequency domain, difference each bin separately and then recombine the bins before going back into the time domain. Adaptive filtering might also work using the motor only channel to "train" the filter. A DSP guy could probably come up with other schemes as well but practically speaking if you aren't trained in the theory and implementation of DSP these techniques are unavailable to you.

Another technique which is available is to go into the frequency domain, find which bins contain the interfering noise (engine) and suppress those bins before going back into the time domain. A module which does this is available in Sound Track Pro and they demonstrate it at their website http://www.apple.com/finalcutstudio/..._2_restoration with this very application (suppressing the sound of a boat motor). You might want to have a look (or rather listen) to see what you think. Quicktime is required.

Haha thats the best part! That and the roaring noise of the tubes riding across the water, 10x better than any sound picked up on the boat.

The Countryman's are definitly out of budget for this, but wow do they look amazing. I think I'm going to try out the condom idea, even though keeping a stockpile of condoms next to my camera equipment will be a hard one to explain to my family...

As far as equiping it on a tuber, i think I'm going to strap the iRiver on the top back of a lifejacket of the middle tuber, with the condomphone sticking out of the top shoulder area (I figure it's the least likely area to hit the tube itself).

Also, what's a cheap microphone you guys would recommend? (I'm pretty sure i'll be using iRiver 790 for recording)