LIWoman:
Well I think you've scared me a little. I'm starting my class next weekend. It's 2 weekends, Saturday and Sunday, both days 9-3. I have had to read and complete the test in the first 3 chapters of the book and watch the video. Is that going to be enough?
I didn't want to scare anyone but that sounds like the typical OW class and many on this board think that necessary skills needed before diving in open water cannot be gained in such a short time. Others disagree and call OW a "license to learn".
I've had several people contact me shortly after taking an OW class like you've described and asking what would be the best way to improve their training and I'm not exactly sure how to answer. Now, I don't know anything about your instructor but the worst case scenario is your instructor is a product of the same system he is teaching and he simply has never learned good technique because no one has ever taught him. I see this all the time at the lakes, an instructor with his octopus and gauges dragging in the silt and fins kicking up the bottom on every stroke.
Now, how can anyone be expected to become a competent diver if they've never been shown or told what a competent diver looks like?
Here are the things I see at the lakes and oceans that are often a product of the diver simply not knowing any better:
1) Not descending or ascending with the buddy. You should be watching your buddy during the ascent and descent as this is one of the most frequent times things go wrong or you get separated.
2) Danglies. Your octopus and SPG/console/whatever should be clipped off somehow, not being dragged on the bottom.
3) Overweighting/trim/buoyancy. This is a product of training/experience but if you don't know what you're striving for, you'll never get there. You want to minimize the amount of weight you have, there are plenty of references to this on this board. You also want to be completely level in the water. If your head is higher than your feet, that means you are kicking up the bottom.
4) Start thinking about gas planning. How much gas would it take to get you and your buddy from your maximum depth to the surface on your tank considering your breathing rates (aka SAC rate).? If you want to learn about this, search the board for "rock bottom".
5) If you are planning on using a dive computer, know how to use it. Understand what it is telling you if you accidentally put it into deco. Regardless of having a computer, you should know how to use tables as well. They can save you from ruining your vacation if your computer dies on you.
I'm sure other people will have many more items they would like to add; these are just some of the most egregious examples I've seen.
Well, good luck to you; diving is a wonderfully amazing experience and I'm sure you will love it.