MHK:
Hundreds and hundreds of them.. I would say that I deny about 75% of my students a passing c-card the first time they take my class, and more often then not it is based upon lack of basic skill(s).. You'll be surprised what happens when you ask divers to do skills while remaining nuetrally bouyant, or you'll be surprised how many students can't remain nuetrally bouyant when you ask them to do nothing but stay still. Then throw in a mask R & R, or an air share and all too many students get tunnel vision and focus on only the air share, or only the mask R & R and loose 5' or 10' of bouyancy. In many cases 20' or more of bouyancy. It happens every week, in almost every class I teach.
What is the remedial training in these cases? I'm sure since it happens to you that often, you run the gammit from: "come and do a pool dive with me" -to- "give me your C-Card you slug and take the full OW again"... Just wondering what you're options are and what you've done in the past. What sorts of reactions have you gotten...
MHK:
Try loosing 10' or 20' of bouyancy while on a mix that drives the PP02's at, or near, acceptable levels? And then ask why wouldn't you want to see your student demonstrate proper bouyancy prior to issuing a c-card with your name on it? No amount of money in the world is worth it, especially what scuba instructors get paid ;-)
But by testing the students for those skills you are opening yourself up to those liability issues. If a student meets the standards (lets hypothetically say all knowledege based, no dives), you sign off the C-Card and then the diver goes and injures themself on the next dive... You could say "look I instructed up to the agencies standards, I'm not required to evaluate buoyancy, etc. I had no idea they couldn't maintain depth while doing X or Y, but they demonstrated the required skills (bookwork) to get the card".
But I realize this thread is evolving... I agree that continuing education is good. Heck, why not require something like an "annual" checkout dive for all divers with less than 100 dives, and "bi-annual" checkout for divers with less than 200, etc... or some similar system... The smart ones will seek out mentors, be that an instructor or divemaster, or Master Diver, or whatever and keep learning...
The origingal question wasn't "Is continuing education good for divers?", it was "Should NITROX certification require actual dives?". I still think my two dives were a waste of time and money as far as NITROX goes, although they were very valuable as far as honing my diving skills goes. I think we agree that continuing education is a VERY GOOD thing for a diver, I just don't think the NITROX class is the setting.
Honestly, do you think PADI or the other agencies see the 2 NITROX dives as an opportunity to provide a refresher or as a way to keep their instructors more employed (ie make a few more bucks)? If they are truly interested in making better divers with these two dives, why don't the published standards reflect that? (what are the standards for the NITROX dives anyways?)
Heck, if PADI (and the other agencies) would hop on scubaboard once in a while, the dive industry would be perfect now wouldn't it???