Honestly one of the dirtiest springs I've ever swam in. The water quality is fine (with low visibility due to many children stirring up the sand), but I discovered a half-dozen plastic bottles full of sand in and around the spring vent. As I took a couple out, I saw children pick them out of the trash and throw them back into the water.
Think of this place like a typical community pool. Even toward the end of the day, there were many, many more children than parents (leading me to believe many of them were dropped off to swim unattended), an entrance fee of $1, poorly run facilities, and a staff that seemed more interested in telling me to, "be careful not to let 'em steal that camera." I was told four or five times that I'd turn my back for a second it would be gone.
Needless to say, I don't really recommend this place unless you get here bright and early. The spring itself has a very interesting landscape along the bottom but isn't really explorable or interesting.
It was later in the day when I first visited Manatee Springs, so that probably already threw off the trip a little. The park was moderately busy but the swimming area wasn't very crowded. With only one entrance to the spring pool area it was a little congested getting into the water, but once afloat there was plenty of room to move around.
It's worth nothing that there's almost nowhere to stand in the pool. As far as I could tell, the water pours out of a cave between 30ft and 40ft below the surface. You can swim to the banks near the cypress trees and barely get your toes on the sand, but for the most part this is a snorkeling and floaty spring only.
Diving down to the cave caught me by surprise as I had to clear my ears three times before getting to the mouth, and even then the force of the water escaping pushed me a good five feet downstream. This free-dive isn't for the feint of heart and could be the deepest I've had to dive to find one (save maybe DeLeon). It's enough to make me want to go back in the morning when the water is clearer and the sun is higher.
The first visit was a bust (March 2010) due to the flooding of the Suwannee. Apparently this happens fairly regularly, so be sure to check ahead to make sure the Springs are open and clear.
The second visit was a pleasant surprise and did not disappoint. I sort of forgot that the park was maintained/owned by Gilchrist county (and thus had an entrance fee), but my $4 was well worth it a few minutes later. The facilities for changing were very nice, and the concession stand wasn't half bad either! With two vents, even the number of people didn't deter me from hopping in and going for the more-eastern vent. While a little scary being all alone in the pool surrounding the boil of this vent, the depth was extraordinary. I was able to dive a good 15 to 20 feet before reaching a horizontal cave gushing clear water. Visibility wasn't great due to all the vegetation, but I'm not sure why the spring showed so little use. I was pleased.
Rather than exit at the beach and walk to the other vent, I chose to swim the gap. Visibility in this area wasn't quite up to what I expected, but it was mostly due to the crowds and sand being kicked up. Swimming a few feet under the surface gave me a better if darker view, spotting many schools of fish darting around unsuspecting visitors. After a quick breath under the bridge I arrived at the pool for the second vent.
I see now why it was more populated and fresh: the walkway above the sharp banks opened a tiny bit to allow jumpers access directly over the boil. It was more difficult to swim in this area due to that fact, but the clarity and force of the water made up for it. Check out the photos below for July 2010; the clarity of some of the later shots is amazing.
A boardwalk takes visitors out to the Suwannee which flows by just a quarter-mile from the springs. Had the mosquitoes and heat not been as bad I may have snapped more shots, but it is nice to take a step away from the crowds and see a seemingly different ecosystem.
Overall, Hart Springs surprised me. I think it's only downside is its location: fairly far from I-75 for hoppers from the east. However, if you ever end up in the High Springs / Suwannee River area, stop by. Just make sure it's in the summer!