I work in Huntsville and it's not a bad place to live in this area. Where are you moving from?
Before you go buy a membership to Rock Divers, See when it expires. If it does at the end of the year or one year from issue. If at the end of the year, then do the math to see if it'd be cheaper just to "pay as you go" based on when the break even point would be.... There's nothing wrong with Rock Divers, but most people want a "change of scenery" and dive other stuff instead of diving it "all the time"
If you want to meet new divers and have a good time at the Madison Quarry, hook up with Dive Sports in Decatur. Once a month they do "Quarry Days" where they do a big event at the quarry. It's the same price as regular admission (if you sign up with Dive Sports for it), but it includes lunch and drinks. Check out
http://www.divesports.com/travelschedule.htm and click on "Quarry Days" for the weekend you're intrested in. (Note: you need to register at least a day beforehand with Dive Sports cause they have to buy food for lunch, etc).
Luke also referenced SEAS, the local Scuba club. It's a great ways for a person new to the area to meet new divers.
Luke hit a good overview of the local quarries and their websites. There's also one other quarry around outside Moulton, AL (about 1 hr from HSV). It's been "re-opened" by a group of divers trying to open a new dive store in Center Star AL (which is so small that it doesn't even have a stop light). They don't have a website, but it's yet another quarry to dive around here. To find this shop, go to the dealer search on Oceanic's dealer page.
http://www.buyoceanic.com/location-dealer-OC116.aspx . You can call the numbe listed to find out more about the quarry and what weekends they may be open. BTW, make sure you take you own tanks there as they have NO facilities there. As for their shop, I don't think it has ever actually opened.
The Tenneesee River dives that SDI does I doubt will be happening anymore. They did these in Florence on Wednesy or Tuesday nights and SDI is closing their Florence store. On their website they said it was due to the poor "economic climate" (poor sales or management) of the area/store.
As for other local "mainstay" shops in the Huntsville area, here's an overview of them and each of their websites: (in no particular order)
Dolphin Aquatics http://www.dolphinaquatics.com/ (NAUI & YMCA) located in north Huntsville on Nick Flickard Rd. They are kinda hard to find and operate really weird hours. (Like they don't open until 2pm or 3pm or something). They have a very nice pool area on site but their store is kinda lacking. They don't have much in stock/inventory and their prices seem to be "list price" on everything. I don't think they do much in sales compared to some of the other stores. Not sure if they do Nitrox or not.... I think this year they are doing a Grand Cayman trip and in the past I've seen them do some Panama City trips, but they don't have much in the way of trips listed on their website.
SDI Scuba on Bob Wallace (
http://www.sdiscuba.com) (PADI). They also have a store in Florence which is closing this summer. They carry a pretty decent selection of equipment, but pricing seems to be list prices and isn't the best (compared to Dive Sports and online vendors). They have Nitrox, but I think it's all "pre banked" 32% and you can't geta varied Nitrox fill. They are open "normal hours" (9 or 10am to 6pm, Monday through Saturday). They do a couple Panama City trips per year plus a trip to Bonaire typically every year, which I hear is a pretty cool trip.
Rock Divers (
http://www.rockdivers.com) (NAUI and maybe others). This store that operates out of a "double wide trailer" at the rock quarry. They do sell gear, but not much and don't keep much in stock. Most of their focus is on managing admission fees to the quarry, air fills, and a couple "paint ball courses" that are onsite. Sometimes the topside there gets a little crowded if they have a big series of paintball tournaments going on. Admission to the quarry is about $18 bucks and they have onsite air fills, but the air fill station there can get kinda crowded and a long wait and you have to drive topside for tank refills. Ask around to see if they are still having oil issues in their compressor. I think they got it fixed, but I haven't checked since. They also offer Nitrox fills there but last weekend they were either out of Nitrox or their Nitrox system was "broken". (A lot of people bring their own tanks here). They are open every day in the summer until 8pm and most days in the winter but they seem to operate their hours at a changing basis "as they want". Some other divers went out after work to do an afternon dive in the past few weeks and they came down and told them at 6pm that they'd have to leave because they were closing (when their published hours are until 8pm). The quarry does have some cool stuff in it though. An F-4 fighter, S-10 pickup, walking bridge span, firetruck, minute man missile, couple house boats, several runabout boats, a few NASA mock-ups, etc. They've also got a Bus that they will put back in sometime after it gets 're-cleaned' of the diesel fuel. Parking is very nice that you can park at the waters edge and they have several nice docks to gear up on and several training platform. Vis can be 10 to 25 feet and water temps get nice (for a quarry) towards the end of the summer. A great place for local diving for $18 bucks.
Dive Sports Scuba (
http://www.divesports.com) (PADI) in Decatur is pretty much the "Premier" dive shop in the Huntsville/Decatur area. They have the biggest selection and best prices on anything in the area. Since they operate this store also as an Internet store, it keeps prices very low but you still have local availability and great customer service. This is also a great way to "pre shop" and see what they've got by going to their website. (They do have other stuff in the store that's not on the website though as I don't think all brands allow internet sales). They will also beat/match any other price you bring them on the same item. They carry most of all the major brands, etc. They are open 9am to 6pm Mon-Sat, but I've found them there as early as 7:30 when stopping in for something before heading to the quarry. They do monthly Panama City trips, Quarry Days, a couple Liveaboards to the Dry Tortugas each year, etc. This year they did a Key Largo trip and have a Nassau trip scheduled for this fall. They have one of the best and newest compressor setups of all the local shops. They have Nitrox and offer partial blending so you can get what ever percent Nitrox you want and they have a new compressor and nitrox blending system with a high quality air filtration system. They are a short drive from Huntsville and well worth the drive.
Hope that all helps some. Feel free to drop me a PM if I can help any.
BTW... we'll be out at the Quarry this up coming Saturday if you make it here
in time and "got the itch to dive". (Except for Luke, he'll still be "stuck" down in the Bahamas diving).
-Mike