We haven't been down to San Marcos in a while. Let's do a quick loop from San Marcos City Park up to Aquarena. Paddle down to Graduation Falls and loop around the diversion channel back up to City Park. See map for detailed route:
You can portage at Rio Vista if you don't want to run the chutes. There is only one other obstacle past Rio Vista, and that's a broken-down dam that can be easily portaged.
This trip is slightly strenuous since we'll be going upstream for part of the trip, and you'll be portaging around Rio Vista at least once.
There is a chance to get wet, so please leave electronics and other valuables in your vehicle, or use a drybox / drybag.
Pack lunch or snack. Definitely pack plenty of fluid.
Wear a hat. Apply sunblock.
Definitely wear PFD.