Mituda
First thing to accept: there are no sand beaches in Batumi. The whole Adjara coast is pebble.
This is a trade, not a flaw. Pebble keeps the water clear even after a swell, while sand clouds it for half a day — any sandy Black Sea resort looks like cocoa after a storm. The price of that clarity is footwear: walking into coarse pebble barefoot is unpleasant on day one and painful by day two.
Second: the beaches here differ by the shape of the sea floor and the number of people, not by surface. That is what to choose on, not the photographs.
Batumi central beach
Right by the boulevard and within walking distance of everything. The upside is obvious: step out of the hotel and you are there, with cafes, rentals and showers alongside. The downside is the same, plus a working port nearby, and the water is no clearer for it.
A sensible choice if swimming is a pleasant addition to the city rather than the point of the trip.
New Boulevard
The seafront continues north among the high-rises. Noticeably fewer people than the centre, a well-kept shore, and still close to town. This is the compromise you pick when you want neither a drive nor a crowd.
Gonio
Fifteen kilometres south. Coarse rounded pebble, a shore running about two kilometres, and above all a gentle entry: the depth builds slowly and the shallows have time to warm. That is why Gonio is most often named the best option on this coast for families.
Gonio fortress is next door — a Roman stronghold first mentioned in the 1st century AD, with walls and towers along almost the whole perimeter. A beach day here turns easily into a full one: half on the water, half among excavations.
Kvariati
Further south, closer to the Turkish border. This is where people most often report the clearest water on the coast, and the reason is simple: the mountains come right down to the sea, there are no large rivers nearby, and so none of the silt they carry.
It is also where the diving groups go out — the only place in the country where diving is properly established. The entry is steeper than at Gonio, so fewer people bring small children.
Sarpi
The southernmost point, right at the Turkish border crossing. A small beach squeezed between cliffs and water, and the water here is very clean too. The place is compact and fills quickly at the height of the season, so morning is worth it.
Kobuleti
Twenty-five kilometres north. The same coastline, quieter and cheaper, with a pebble strip running the length of the town. The water deepens quickly and the surf is stronger than in Batumi, worth noting if you are not a confident swimmer or travelling with children.
In exchange you get what Batumi does not have nearby: the Chakvi tea plantations, where Georgian tea growing began in the late 19th century, and Mtirala national park.
More: Kobuleti.
Ureki
Strictly speaking this is no longer Adjara but Guria, about an hour from Batumi. It is the only place nearby with sand instead of pebble — black, with magnetite in it.
The magnetite makes the sand heat up strongly in the sun and hold the warmth longer than usual; it is credited with healing properties, and families have long come here for it. The entry is gentle and stays shallow longer than anywhere else on this coast. There is almost no resort development, and pine forest runs right up to the shore, noticeably cooler in the heat.
More: Ureki.
The short version
When to go
The swimming season runs from mid-June to late September. An important detail: the water warms later here than at other Black Sea resorts, and in early June it is still cool while the air is already summery. People who arrive in early June "for the sea" often never actually get in.
September is usually the best month: the sea is warm after a whole summer and the main wave of visitors has gone. October is no longer about swimming, but mountain Adjara is at its best then, and a day in the hills easily replaces a day on the beach.
Getting between beaches
Gonio, Kvariati and Sarpi sit on the same road south, twenty to thirty minutes to each. Minibuses run in summer, but with beach gear, an umbrella and children that is a doubtful pleasure.
A transfer for a specific trip is simpler, especially to Ureki, which takes longest by public transport. You can also see the coast down to Ureki in a day: the Petra Fortress and magnetic beach trip.