A few other options come to mind:
Devils Den in Willison is about 2 1/2 hours from you: it's an easy freshwater dive where you can practice your buoyancy: they have several underwater platforms. It's a fun enough dive as well though I'd not go out of my way to dive it unless I was in the area.
Scuba Shore Diving Site Page for: Devil's Den of Florida, USA East
Devils Den Springs Scuba Diving Resort
Rainbow River is about 2 hours north of you. It's an ultra shallow, low stress, fresh water dive where you can practice buoyancy. I went with American Pro on my trip but I think Bird's goes there too. Both of the shops are actually located in Crystal River
Manatee Vacation in the Florida Springs
Venice is only an hour away and is one of the best shark and fossil diving sites in the country. Vis isn't very good, but its shallow and you can practice your skills. You'll probably enjoy sifting in the sand for shark teeth and build the confidence that if you can dive with 5 feet of visibility comfortably, you can dive almost anywhere an OW cert will take you in Florida. (google 'venice shark tooth dive' for operators).
Jupiter is great and I dive here several times a month, year round, with JDC. I know Jupiter Dive Center certifies a lot of OW divers off of their boats, but I would have been somewhat intimidated if I had tried diving the area before I had 25 dives or so. But that might just be me and my conservative nature. I'm not sure that staying on top of the reef with only 25 minutes of dive time would be all that fun either.
If you'd be willing to drive just a bit further south, Boynton and WPB have a lot of 60 foot dives that easily fit in your OW certification. Even on air, you can get decent bottom time if you stay on top of the reefs. The Scuba Club in WPB is really good with newer divers since they usually send a least two guides down (one for air divers and one for nitrox divers). My main beef with this operator is the number of one tank dives it operates. Note that Boynton boats generally do not send guides down with the divers and while most of the WPB shops do, the single guide usually stays down until the nitrox divers are done: so air divers surface before the guide. Other operators include Jim Abernathy Scuba Adventures, Scuba Works boat off of PGA, Sandy's Sunday, Narcosis (probably better once you have a few more dives under your belt), Underwater Explorers, Splashdown.
If you'd be willing to drive just bit further, Pompano has some really easy shallow but beautiful reef dives. South Florida Dive HQ, Pompano Dive Center and Scubatyme are operators I've used. SFDHQ regularly goes to the shallow sites, but the other two do occasionally as well. Again, no guides, but you don't need one in 30 feet of water: if you get lost, just pop up and look for the dive boat. If traffic is light, you can make it to Pompano in 3 1/2 hours.
Blue Heron Bridge is a great shallow beach site in WPB that you can dive at slack high tide. If you're uncomfortable for any reason, hire a guide from Force-E or Pura Vida: both shops are nearby. See the Blue Heron Bridge Trolls thread for info or
Blue Heron Bridge
