As a newbie diver, I am going to climb onto a high horse here that I don't own. I hope you'll forgive the indulgence.
1. If you can't afford a dive watch that is good to 100ft, you don't need to have SCUBA gear on your back. One of my dive watches was less than $7 at Wal-Mart, and yes I DID take it to 100ft.
2. If, as an instructor, you don't require your students to have a means to time their dives and work the tables BY HAND, you should have your instructor card removed on the spot. Period. I don't give a rats ***** what agency you instruct for.
3. As a student, if you leave dive class without a fundamental understanding of how to follow the dive tables, you don't need to be a diver. This is like taking a driving course and never learning how to use the brakes. Foolhardy, and potentially deadly.
4. It is *MY OPINION* that EVERY OW diver should have to learn to dive with a depth guage, a watch, and an SPG as their only instrumentation. I did my first 30 dives this way.
I could go on, but these are my huge pet peeves. Hopefully I don't piss anyone off too badly with them, but that's just the way I feel.
Again, thanks for your indulgence.