Here's a bit of a jumbled update.
The S100 is pretty sweet. IQ isn't bad at all. I'm impressed with the fully auto mode and it's focus tracking abilities. The manual options are a bit clunky, shooting RAW is fairly slow.
Full HD footage hits the 4gb limit within about 15-18minutes. 720p lasts 22min or so. A bit annoying, but I think ultimately this was the better choice than a dedicated video camera as it'll get more use, the CHDK is in alpha at the moment, so in another month or so I should be able to add interval shooting and motion detection to the camera, which should be sweet. Also, work is looking into getting the Contour camera for a similar project that they've started to consult me on
Still waiting on the housing, which hopefully will arrive today. It's been a challenge getting one as my local shop sold out, and 3 different online shops that listed them as in stock actually had them on back order. Ended up getting a housing from Amazon.
As to the frame, I've got a sheet of Aluminium from the Tech school at Uni. I've drilled out 5.5mm diameter holes, and had to order some 1/4" 20 tpi bolts off of the internet as our metric 1/4" bolts are actually 25 threads per inch so don't fit camera threads.
I'm hoping to get some rope later this week, and test the housing in a water butt. Then this weekend will be deployment #2. I'll also try the camera with CrabCam MkI for some baited footage too.