Both cities fly the standard Gulf Coast flag system, and it is posted at the access rather than buried on a website. Purple warns of dangerous marine life, which here usually means a jellyfish bloom. Yellow is moderate surf or a moderate pull. One red flag is a high hazard. Two red flags together mean the water is shut. Green, which visitors see rather less often than they expect, means conditions are calm.
The double red is the one visitors misread. On this stretch of Alabama coast it is not a strong recommendation, it is a closure, and entering the Gulf while it is flying has been treated as a citable offence in recent years rather than a matter for a lifeguard's judgement. Penalties are set by municipal ordinance and have been revised more than once, so check the current position with the city, but plan your week on the assumption that a double red means the beach day becomes a lake day or a trail day.
The reason is structural rather than fussy. The bar-and-trough profile off this shore builds rip currents that run seaward through gaps in the sandbar, and they are strongest on exactly the days when the surf looks most fun. If you are caught in one, do not swim towards the beach. Swim parallel to it until the pull stops, then come in at an angle.
There is no shade, no drinking fountain on the sand, and the quartz reflects a serious amount of ultraviolet back upwards. People underestimate it every single week of the summer.