The one-piece stopped being the conservative choice around the time swimwear brands started designing for the whole day rather than for the water. A maillot with a high leg and a low back is not modest. It is structural, and it is the only swim shape that sits under a sarong without a visible seam fighting the drape.

The market followed. Independent swim labels now cut Italian and Portuguese fabric at weights that hold their shape after chlorine, and they price accordingly. The eight below run $168 to $225, which is the current floor for that construction rather than the ceiling.

Within that narrow band the differences are real. Left On Friday and Éterne cut clean and plain, no hardware anywhere. Ay Que Calor and La Porte use print. Baobab and Onia go for colour and texture. Tropic of C's Orb is strapless and belted, the only suit here with hardware at the waist. Mare Perpetua's Seek is the closest thing to a plain ivory suit, which is the hardest version to make well and the easiest to ruin with sunscreen.

What goes over the swimsuit is now a bigger business than the swimsuit. Sarong and pareo are two names for the same garment, and both have moved from resort gift shop to designer assortment in roughly a decade.

The reason is commercial. A pareo is one piece of fabric, so it carries no size, almost no fit risk and a very low return rate, which makes it one of the most profitable things on a swim rail. For the person packing, it does three jobs at once: a skirt at lunch, a wrap on a sunbed, and a towel when there is no towel.

The eight here run $85 to $400. Meridian at $85 is the plain chiffon version that does the job and nothing else. Jacquemus at $400 is printed cotton and silk and reads as clothing. Johanna Ortiz prints hers the way a scarf is printed. Toteme's Collector is the logo version. Onia's knitted linen mini and Baobab's ruched maxi are the two that behave most like actual skirts, which matters if you want to walk into a restaurant without changing first.

The last layer is the one people underpack. A slide is built to come off without bending down, which is the whole point beside a pool. Marc Jacobs, Burberry and Tory Burch all build theirs on a moulded footbed, and that is the difference between a pool shoe and a shoe that slowly becomes one. The Tory Burch is the raffia version, and the one that looks least out of place once you are off the tiles and walking to lunch.

Sunglasses take more damage at a pool than anywhere else, between sunscreen, salt and being sat on. Acetate handles that better than thin metal, and both Saint Laurent and Fendi name acetate in the frame. Lowercase is the quieter, squarer option of the three.

Sun care is the only part of this page that is not optional, and it is also the cheapest. Supergoop's Mattescreen is mineral and dries down flat rather than shiny. The Dior fluid sits under everything without leaving a white cast, which is the thing that ruins photographs taken in full sun. Prices across the grid run $40 to $425, and the $40 item is the one doing the most work in it.