I reviewed the two trunked systems in Nueces County. I don't know if the "Four County Coastal Bend INTEROP System" is still operative. If it is, there is a talk groups for Beach Patrol, 02-042, North Padre Island Beach Patrol.
On the "Coastal Bend Regional Interoperability Network", I see Corpus Christi & Port Aransas talk groups only. Since this is a new system, an ID search might be in order provided you are using a Phase II scanner.
There is another possibility. Under the Nueces conventional frequencies, there are two channels for the Federal Rangers for the Padre Island National Seashore, one analog and one P25. There is also a P25 frequency for Turtle Beach. All three of these are Federal.
Which radio are you using there?