I've done 30m which with a few of mine. 40m is usually the maximum for recreational diving before you get into technical diving. I know people who have gone down to 75-100m but really unless you are wreck diving there's no that much to see at those depths as all of the "pretty" marine life is 40m and above.
There are people that do deeper dives for oil rig / pipeline work and maintenance but that is hugely specialist and hugely dangerous, but very, very well paid.
Everyone uses digital dive computers now anyway so the point is moot. I only use my dive watches as a back up to my computer.
tl;dr - depth markings over 100m are usually a statement of quality rather than useful user guidance.
(PADI Advanced Open Water with NITROX certification and 50 dives - L&W has 200 dives and is a certified Dive Master)