Anyone With Pelican Case Experience?

Since the beginning of the kayak photography adventure, I've been researching ways to provide additional protection for the camera gear while on the water.

I haven't made a purchase yet, but have been leaning toward the Pelican hard cases and was wondering if anyone out there has experience with them and would be willing to offer up an opinion?

My criteria are as follow:

1. Needs to be watertight when latched.  Generally speaking, the worst that "should" happen would be rain and/or water spray, but...
2. Ideally it should float - even when loaded down with gear.  Would most likely tether the case to the kayak, but if it flips over, there's the possibility of being submerged.
3. Provides shock protection for stored gear if dropped, bumped, jostled, etc.

While it's true that my greatest source of protection when having the camera gear on the water would be my common sense, there may be occasions when one could be surprised by weather or the curiosity of a deep sea monster flipping your kayak!

So, does anyone have an opinion on these Pelican cases?  Is it worth the investment for what we need it to do?