Aqua socks: sizing down, sole thickness and where they give up

A water shoe is a stretch fabric upper over a thin rubber sole, made to be worn wet. It is not a sandal and it is not a trainer. It exists to stop a rock, a shell or hot sand from ruining an afternoon, and to come off a foot without a buckle.

Size down, not up

This is the one place in the catalog where the maker says to go smaller, and the reason is physical rather than about the pattern. The upper is elastic. A loose aqua sock fills with water, the water adds weight, the shoe slides forward and the heel comes away on every step. Its own bullet points recommend about half a size smaller than usual.

A correctly sized pair feels slightly tight in a dry shop and normal in the water. If it feels comfortable dry, it is too big.

Sole thickness

The listings differ here and it is worth reading. A thicker sole protects better on a stony beach and lasts longer where the upper meets the rubber, which is where these shoes fail first. A thinner sole folds smaller and gives more feel underfoot, which matters if you are on a boat deck or doing anything where grip on a smooth surface counts.

• Rocky shore, river bed, water park: take the thicker sole.
• Pool deck, boat, yoga, travel where space is tight: thinner is fine.
• Hot sand: thickness is the whole point. Thin soles conduct heat.

The five toe version

One listing splits the front into separate toes. It grips better on wet rock because the toes can spread and it feels closer to barefoot. It also takes a minute to put on, is harder to get on with wet feet, and is unpleasant if your second toe is longer than your first. Try the standard shape before spending twenty dollars on the split one.

What they are not

1. Not walking shoes. There is no arch support and no cushioning. A mile on pavement will be felt.
2. Not reef protection for the reef. A hard sole on coral does damage regardless of what it does for your foot.
3. Not warm. Wet fabric on a windy beach is colder than bare skin.

Making them last

Rinse in fresh water the same day. Salt crystallises in the elastic and chlorine breaks it down, and both shorten the life of the upper more than any amount of walking does. Dry them upside down and out of direct sun. Keep them out of the washing machine, because the sole is glued and the agitation separates it.

Treated that way a ten dollar pair does three or four holidays. Left wet in a bag they smell after one and split at the toe seam by the second.

Buying for a family

These come in a wide range of sizes and colours, and the colour is doing work when four people leave four pairs at the edge of a pool. Buy different colours on purpose. It is a small thing that saves an argument.