OK I am about to take the plunge and buy a M900 to strap on my FF RAS.  I see a couple of people offer a "waterproof" version which is $100 to $150 more expensive.  How "waterproof" is the regular model and how "waterproof" is the waterproofed model?  What is done to the light to make it $100-150 more expensive?  Does it retain the lockout tail switch?  Any help appreciated.

Can you show me the links to the waterproof M900's and a link to one that is not waterproof?

http://onestopknifeshop.com/store/surefire-special-operations-lights.html

Waterproof DEVGROUP Version available by Special Order (white navigation LED's only).


ALSO at Sableco.  

http://www.sableco.net/id18.htm

M900AN-WH Vertical Grip with White LED Navigation Lights, Waterproof $490

Both come as waterproof "A" versions with white LEDs.  No other LED or "AB" turbo head models available.

Are you thinking about upgrading new-arguy?  If you are you know I have to buy this thing...  Your AR collection makes me so jeleous I turn green everytime you post em!  Especially that SIR-M/M900A/TA31 Bushmaster.  That rifle is the reason I restarted the buildup of my NIB preban Bushy after a year layoff from buying guns.

It's the "N" (for Navy) in the part id that tells you it's been pressure tested to 20 metres water depth.

Al

Edited to correct the metres depth.

Well, If there's one thing I seriously get into aside from AR's its Surefire lights. I really love them. My collection of Surefire lights rivals my ARs... I dont know everything about Surefires, but I thought if there was a waterproofed M900, I would have known. But I had no idea this Devgroup model existed. Pretty cool.

While I dount I'll upgrade, I am glad to know one exists. If I didnt get such a good deal on the one I have, and was in the market for one, I would probably try to get the Devgroup model.

Coincidentally, onestopknifeshop.com is very close to where I live... But my "go-to" guy for all Surefire's and AR gear is SABLE Co. Email Donnie from SABLE Co and see if he can get the Devgroup waterproofed M900. He may or may not know about it either. You can direct him to this post if he doesn't. See what he can do and compare prices...

Thanks for the info!

Well umm... I cited Sableco as one of the 2 (two) companies that were selling it...  you will notice it right under the first ad.

I Emailed Donnie already and he doesnt know anything about the waterproof model...he just sells em for less

I will put in a call to Surefire in the morning and find out all the info I can and post it here.

I worked directly for SureFire for quite some time, and I was not aware of a Waterproof version of the M900.

But...things change fast over there.

It may have an N rating, meaning they took a stock M900 and actually pressure tested it to ensure that it would still function following the test.

Most SureFire's are water resistant, that is rain and short, shallow immersions etc don't bother them.  Some you can dive with and they work just fine.  Others in the same model leak.  They are not waterproof.  Should be in my opinion, but they are not.

You can even take the Polymer Series - "P" model handgun lights that leak like a sieve and put them in water all night.  Open them up, drain the water and they work.  

I used an M900A when they first arrived on the scene, and noted that when they got even the slightest amount of moisture inside, the LED lamps would "glow".  The light still worked, but if you were in an environment where compromise could be an issue, the LED's glowing, did not give a "warm fuzzy".  

I chose to "waterproof" mine by using RTV and sealing up any exposed wiring and any and all gaps I could find in the housing.  This worked against large splashes of water. Unless you plan on swimming with it, you may prefer the cheaper method.  This method, however, WILL VOID YOUR WARRANTY.  

I have since (two weeks ago) asked Sure-fire about a waterproof model, and they did in fact tell me that the "N" model was in production.  

I can only imagine the hike in the prices though.

OK I talked to Surefire customer assistance today.  He told me the Waterproof unit has double O-rings, is made to tighter specs and uses dielectric grease on all fittings.  Then they are sent in batches to be tested for deep water submersion.  The regular versions are NOT warrantied for use in salt water.  The waterproof version IS.

It appears to me the waterproof version is better at repelling water but it is only a small part of the process.  The majority of the cost appears to be the testing for water depth/pressure and the extra warranty provided.  They also told me to expect a month wait for a waterproof "N" version since they wait till they have several because of the cost of certification.

He also told me he had not heard of the "glowing LEDs" problem but said that it would not supprise him.  He assured me this would not happen with the waterproof version.  All in all I think there are enough points (barely) to justify its purchase.  Surefire told me they could start building me one for sevenhundred and some odd dollars...  I told em "Uhh... lemme think about that one."

Thank GOD Donnie sells em at $490... the same as the turbo head model.

Edited to add They are water proofed to Navy standard for electronics which is 20m / 66ft / 2 Atmospheres

Fantastic info... I'm glad to hear about it. I'm suspicious however. So few people knew exactly what this was. Heck, Ken didnt even know. SABLE Co already said he wasnt aware. I would suspect he didnt have any in stock, though he does list it on the site. I wonder if he actually tried to order one, if he would still be able to sell it at that price?