My two cents:
1.If you paid waterproofing/water resistancy from the dealers, then that means you could swim with it! That's what you're paying for! I know some members will not take the dealers word for anything, but since I paid for it, it better be water resistant or else it goes back and I'm not scared in dunking it in water! Done that several times!
2. Only the SSD and SFSO are guaranteed by some dealers up to 100M, the new Heritage and GMT IIc are guaranteed to 30M. This is according to there web site and I take there word for it. If it leaks, it goes back. Done that, too! Again, some members will disagree!
3. I don't trust most Chronos and none screw type crown models, so I don't get them close to water not unless guaranteed or waterproof by a modder or the dealer like my '06 Costeau.
4. After my 6th collection and got educated here, I started doing my own waterproofing which is basically opening the case and making sure it has a rubber gasket and the tube or crown and greasing these parts and then tightening them after. So far, been 100% on this little project! All the PAMs I have are water resistant except the chrono models like the 253. That one I ordered from the dealer with waterproofing and it leaked after 3 months! Off it went to the dealer! Now it's ok after it came back! BTW: This was my 5th collection!
Good luck!
Oh, I forgot; go to ofrei.com and get some of the grease and the Ball case opener if you want to do it yourself.