The Beach, Block by Block

The beach in front of Ocean Drive is not natural, and that is the most useful thing to know about it.

By the 1970s, decades of seawalls and hotel construction had eaten the sand almost entirely. In places the Atlantic came up to the back of the buildings. Between 1975 and 1982 the US Army Corps of Engineers ran a series of contracts that dredged offshore sand and rebuilt the entire Miami-Dade shoreline, placing something in the region of fourteen million cubic yards along Miami Beach's six miles and producing a beach roughly three hundred feet wide.

Everything about the experience follows from that. The walk from the dune line to the water is genuinely long, and on a July afternoon the dry sand in the middle of it is hot enough to blister. The dune ridge between the beach and Lummus Park is a planted, engineered structure of sea oats and sea grape, which is why there are boardwalk crossovers and why walking through the vegetation is both illegal and pointless. The beach is topped up again periodically. It is a piece of civic infrastructure that happens to be pleasant to lie on.

Which block to choose

The sand runs unbroken for the whole length of South Beach, but the character changes every few blocks.

If you want the fewest people for the least effort, walk north. The crowd density drops sharply above about 16th Street and almost nobody bothers.

The lifeguard towers, which are buildings

The towers are not generic. After Hurricane Andrew destroyed the old stands in 1992, the architect William Lane was commissioned to design replacements, and what followed was a set of individually designed structures, some by Lane, others through commissions and competitions. There are somewhere between about thirty and thirty-six of them along the city's coast, from the tip at South Pointe up into the eighties.

They are identified by the street they stand on rather than by number, so "meet me at 10th Street" means the tower, and everybody understands it. The one at 13th Street, with the American flag motif, is the single most photographed object on this beach after the sand itself. The 5th Street tower marks the southern edge of Lummus Park.

Swim in front of one. That is not a style note.

Flags, rips and the things that actually hurt people

The flags flying at the towers are the standard Florida system and they are not decorative.

• Green — calm conditions, low hazard.
• Yellow — moderate surf or current. Most days here.
• Red — high hazard. Stay out of the water.
• Double red — the water is closed.
• Purple — dangerous marine life, which on this coast usually means Portuguese man o' war blown in on an easterly.

Rip currents

Rip currents are the genuine risk. They form in the gaps between sandbars and pull straight out, not under. If you are caught in one, do not swim against it. Swim parallel to the shore until you are clear, then come in at an angle, and raise an arm if you cannot.

Sun and lightning

The other two hazards are less dramatic and more common: sunburn, because the UV index in South Florida is high enough to burn fair skin in well under half an hour for most of the year, and lightning. When the towers clear the water for an approaching storm, get out. Afternoon thunderstorms from June to September arrive fast.

Seaweed, honestly

Sargassum is a floating brown algae that drifts across the Atlantic and arrives on the Gulf Stream. On this coast it tends to show up from around April and can persist through the summer, and recent years have brought record quantities into the Caribbean and South Florida.

What it is like on the sand

It is harmless in the water and unpleasant on the sand, where it dries, darkens and smells of sulphur within a day or two. The city clears the tourist blocks mechanically, so the stretch in front of Ocean Drive is usually groomed by early morning and the quieter northern blocks less so. If a photograph matters to you, go early and go where the tractors have been.

Do not let it decide your trip. A sargassum summer is still a swimmable summer, and the water beyond the wrack line is usually clear.

What it costs, and what it does not

The sand is public and free. There is no gate, no wristband, no fee, and public access runs down almost every numbered street. Anybody telling you otherwise is selling a lounger.

The loungers and umbrellas lined up behind the dune are concessions, priced by the set and by the day, and two loungers with shade comes to a figure people repeat to each other in disbelief. Bring a towel. If you want shade, a cheap umbrella from a shop on Washington Avenue costs less than a single day's rental and you can leave it behind.

Restrooms and cold showers sit at intervals through Lummus Park, along with the concession buildings. The Beachwalk runs behind the dune for the length of the island and continues north for several miles, which is the best flat run or cycle in Miami-Dade.

The posted rules people break

No alcohol on the sand. No glass containers. No dogs on the beach. Smoking is banned on Miami Beach's public beaches and in its parks. No open fires, no amplified sound, no commercial photography without a permit. All of it is signed at the crossovers and all of it is enforced, particularly in March.

Topless sunbathing is customary and generally tolerated on parts of South Beach, though it is not an official designation. The county's formally clothing-optional beach is Haulover Park, several miles north and a different trip.