It would be with my K7 and 50-135 or 18-55 WR lens, naked! The camera of course. (though I haven't yet - I did once take out my 50-135 and K20d out in the pouring rain. No problem at all). I love my pentax stuff for being built like a tank and weather sealed.
Brianetta, have you considered buying a cheap polarizer and discarding the filter glass from the mount. That would leave you with an empty filter mount that rotates. You could replace the polarizer glass with clear uv glass, or just screw the empty polarizer mount onto the back of a decent UV filter. Either way the lens barrel would be free to rotate after it had been attached to the rear of the housing for the polarizing filter.