The USCG operates HH-65 Dolphins (150nm range/ 4 Hour endurance) from Corpus Christi, Houston, New Orleans, and Mobile.
The HH-60's operate out of Mobile....which is at the far eastern end of the oil patch thus quite removed from the area of most operations.
That does not consider any Cutter based aircraft that might be in the oil patch.
The USCG relies upon surface vessels for its SAR function to a greater degree than they do helicopters.
The helicopters are assisted by three different types of airplanes primarily Falcons and Hercs.