this post is only for the peace of mind of the 5d mkII owners - your camera is WATER Sealed !!!
when I was in New Zealand I managed to slip from some rocks into the sea while holding my camera trying to photograph some fishermen.the camera and lens (canon 16-35mm mk I) went in the water for about 5 seconds at a 20cm depth before I could climb out.I thought that was it for both of them but....the only bad thing that happened was that 2 drops of sea water entered the lens somehow right under the front element (It had no filter attached) but the body was ok.so ok that I gave the camera to one of the fishermen while being in the water and he took two pictures of me getting out.I removed the battery after that and with water pouring from the camera I went home.I rinsed it with fresh water in the sink,I left it for the night to dry and it works fine since then.the only problem I had was with the lens,after it dried out two spots made of salt remained on the glass under the front element,but I am sure that if I had an UV filter i wouldn