I live in Freeport 45 miles south of Galveston Park and now is not the best time to swim here.We had a very bad problem with seaweed at this time.Happybooker1 is also right about water ,I don't know about the lower coast but with all the flooding must of the water is very dark .August and September are great around here we won't have the clearity in the water but it is a blue -green until the wind changes for Fall.As for camping,tent stakes change to small screw stakes or 1 inch pvc pipes cut to 2 foot with a hole drill in top for attaching tent to.Always try to put extra ground cover before set up of tent .And a must a broom to keep sand out of tents.Have you looked up Matagordo bay Nature Park,nice place,check it out at LCRA/parks.Its a new park ,but you will still have the same water color.In the Freeport area theres Quintana park small but very clean park ,also San Louis Pass Park look under Brazosport,Texas plus we have 5 public beaches.
The sand is also very different from lower coast we have a more dense and pack sand and Pins is a very soft light pack type.
Pinns is one of Texas's best beach areas ,as for 4 wheel drive much of the time the sand is packed down enough to drive.and even then rangers patrol with 4 wheelers and 4 wheel drives to help out if you do get stuck.There is always people around to help,go have fun.Take fire wood,at times driftwood is'nt there.Wash bucket or portable shower to rinse sand off before getting into tents.
Both areas are very different,have fun .
srds
Good Camping