What exactly is "deep hole"? I am assuming this is in very shallow water (I assume this because I always thought TX waters were dark and murky). Either way, I wish we had something like this around here.
I wish we had Thousand Islands.
Texas lakes are generally pretty murky. I think the only natural one we have is
Caddo Lake formed by a massive log jam before the area was invaded by Europeans. That jam was eventually removed, by logging interests wanting to float logs downstream I suppose, lowering the lake, but then a dam was built so it's not actually natural anymore. Like many, it's under pressure from invasive exotic plants.
Spring Lake in San Marco was an area of springs which
"Early travelers and settlers described the large ones as fountains, gushing water several feet above the surface of the stream they created. Today, the Springs lie at the bottom of Spring Lake and are viewed through the floor of glass-bottomed boats. The Springs and the short 3.8 mile San Marcos River below them have been designated as critical habitat for five endangered species, including the Fountain Darter, the Texas Blind Salamander, the San Marcos Salamander, the San Marcos gambusia, and Texas Wild Rice."
General Edward Burleson built the dam in 1849 to operate a gristmill, inundating the Springs and forming Spring Lake, which of course ruined the natural area but protecting artifacts.
"The dam suffered major damage during floods in October of 1998 and some argued it should have been removed instead of repaired. They argue the dam may actually be a threat to the endangered species present, and they point out that perhaps the most educational thing that could be done would be to let the area revert to it's natural state. The Univerisity and federal officials have a different opinion. The US Fish and Wildlife Service argues the endangered species have adapted to Spring Lake and would be worse off without it." more here
It was our first amusement park of sorts. I remember visiting it in 1965 on a school trip, seeing the mermaids & pig from the theater and it was still a hit then. I took my daughter in 1988 but it was barely still open with competition from the original Six Flags park and others, since closing, and so on. That area too is under siege from invasive exotic plants and that was the primary focus of our class when I went one year.
If you lay on the bottom of Deep Hole and stick your depth gauge as far down the spring as you can, you can get 28'. The spring named Deep Hole is one of hundreds in the lake.
Spring Lake is an ex filtration zone of the Edwards Aquifer. A limestone karst aquifer that is essentially the same as you find in Florida and the Yucatan.
On a very bad day the vis is 40'. The temperature is a constant 70 degrees year round (making the lake very popular for classes in the winter). The flow from the springs is rarely below 100cfs. Today the flow is a very healthy 226cfs.
Great place to dive, and if you live locally the Diving for Science Class is a bargain (lifetime certification to dive the lake with no admission fees and they will fill your tank at the end of the dive).
I enjoyed the class and only wished I lived close enough to be a volunteer, but flying to Austin or San Antonio, renting a car, booking a hotel makes it almost as expensive as Cozumel for me. Aren't there some other entrances to the aquifer in the area dived by cave divers?
