Texas is a pretty big state, so it really depends where in South Texas you are...
Will you be on the coast (near Corpus Christi or in the valley) or maybe in the San Antonio area?
There are a lot of great places to Kayak along the coast. You can find kayak trails if you do a search in the Texas Parks & Wildlife website.
If you're in the San Antonio area, there are some lakes and rivers that offer great kayaking! Just be aware that some of the rivers are shallow in places...
Psalm 23:4 Even though I walk through the valley of the shadow of death, I will fear no evil, for you are with me; your rod and your staff, they comfort me.