No flip-flops in soft sand.

They’ll either slip off or make you walk like a penguin. For soft sand all day, you want something with a heel strap and a grippy sole.

The problem with flip-flops on soft sand is that each step forces your toes to claw for grip, which leads to fatigue and blisters. Even good flip-flops don’t fix the physics — your foot slides forward and your toes overwork. The traction on most flat-soled flip-flops is also useless once you hit loose sand.

What works: a sport sandal with a secure strap system and a rugged outsole. Teva Hurricane XLT2 or the Chaco Z/1 are the usual suspects. They’re ugly- stylish in that outdoorsy way, but they grip sand like tires. If you want something less tactical, look at the Birkenstock Milano (the two-strap with back strap) in EVA — lighter, still holds your foot, and the cork bed isn’t hopeless in sand. Or the Merrell Terran Ari, which looks a bit more like a casual shoe but performs well.

Walking in soft sand is already harder on your legs. Don’t make it worse with shoes that fight you.

Buy the strap sandals, save your calves.