Took them all down 8 feet in the pool.  Pressed the on switches 1/2 dozen times each.

ALL of them leaked.

The maglite adjustable lens assembly leaked.

Both Surefires leaked in the tailcaps - I could see bubbles as I pressed the switches at about 3ft

All continued working.

The G2 and old 6P models have TailCaps that are not sealed - if you unscrew the TailCap, you will be able to remove the inside of the switch, and the rubber switch button.

SureFire have a waterproof TailCap pressure switch for the 6P called the Z41. The Z41 also has the ability to be Locked Out.

The G2Z has a LockOut TailCap. I would be more confident of taking the G2Z underwater then the G2.

I quit buying into the "waterproof" advertisements.  I have yet to find any tac-light that has proven to be truly waterproof, including those marketed by sure-fire to be waterproof.  Most are extremely water resistant, but given enough exposure, they all end up either flooding out, or corroding from the inside out. At least the ones marketed by sure-fire as waterproof, tend to last much longer than the others.  

About 15 years ago Ilearned to dive.A friend and I were taking an advanced course in Santa Rosa New Mexico. There is a huge artesian well there called "The Blue Hole", and it is about 100 ft deep. We did a night dive into this thing, and since we didn't have any dive lights we went to the local hardware store and bought a couple of Duracel brand flashlights that were supposed to be waterproof. Whe had em down around 50-60 feet that night and neither one of em leaked.The only problem was that at about a 10 ft depth the switches quit working due to the pressure on them. So they stayed on, or off depending on how you started. Pretty cool for a light that cost around $10!

I took my 6P (new/current one) and
M962SU had no prob. 3 meters underwater

you can see the resulting corrosion I got on my P61 bulb from taking it in the pool.

This is after I disassembled the light, dried the parts and left them on a table to dry for a couple hours.  [:(]

[b]6P vs 950 dissassembled[/b]
[img]http://photos.ar15.com/WS_Content/ImageGallery/Attachments/DownloadAttach.asp?sAccountUnq=141&iGalleryUnq=995&iImageUnq=16630[/img]