I asked a similar question earlier in the year. It depends a bit on what section of Myrtle Beach that you'll be staying. Towards the north, you've already been told about Little River. If on the southern end, then you would have Murrells Inlet and Huntington Beach State Park.

I understand you can go to the State Park and fish both the inlet opening and sections of the marsh around it. It may take some walking from what I can tell. There is a parking lot and it is about a mile or so to the mouth of the inlet. There is a jetty and I think you are allowed to fish from it.

Hope this helps.

John

PS: Have you tried calling the Bass Pro Shops in MB? They might be of some help.