Helicopter over east beaches last weekend???

Did anybody see the red helicopter towing the "missile looking thing" over the east beaches last Saturday & Sunday? They were flying from behind the mountains to several miles offshore, turning around and heading back, moving 1/4 mile west every pass, in a grid pattern. Recording something, I assume, but what?

I heard they were doing a geo survey or it was a magnetometer (?) to measure magnetic field of the earth for minerals.

I think they were looking for illegal aliens. They are swarming over the border ya know and not getting their FMM either.

Hate it when I lose my keys on the beach.

It's going to look like the texas coast