Ok this may be a dumb question but oh well. When using nitrox does it accually allow you to stay down longer or will your dive times be similar to a normal air fill and just have shorter surface intervals? I dont know if if that question makes sense...
Not a dumb question.
You'll learn this in your class.
The basic premise of EAN is that N (nitrogen) is gas that controls your NDL. If you offset the N with something else, in EAN, it is O2 (oxygen), you can extend your bottom time. There are limits of depth due to O2 toxicity.
Using PADI tables, at 60fsw, you get 55mins. Using the SDI Nitrox table, using an FO2 (%O2) of 32%, at 60fsw, you get an EAD (equivalent air depth) of 50ft. Look at your air table at 50ft, which in this case gives you an NDL of 80mins.
I think that is about right. Frankly I'm not a big fan of the ole tables.
As part of your class you'll learn about the partial pressure of O2 and how to calculate it. You'll learn about the MOD of a particular % of O2 and how to calculate it.
It is a shallow gas. It isn't going to allow you to go deeper and stay long.
It will allow you to stay longer in shallower depths.
Good luck!
BTW - They are going to tell you this and teach you this. They are going to teach you to clearly mark your tank with nitrox stickers. Don't. Mark it however you need to so YOU know what you have in your tank, the date of the contents and the MOD. I now use a piece of duct tape. I found some dive shops in FL wouldn't put air in my tanks because they had Nitrox stickers on them They had air in them to begin with. It was some silly 'insurance' thing. In order to get them to fill them, they would have to VIP them. I found another dive shop that handled NITROX and would will them with air.