Peel half of the cucumbers, leaving the remaining cucumbers unpeeled. Using a sharp knife or a mandoline, very thinly slice the cucumbers crosswise. Set aside.
In a medium bowl, whisk together vinegar, sugar, ginger, and salt until sugar has dissolved. Add cucumbers and toss to combine. Let marinate, refrigerated, for 3 hours. Using a slotted spoon, transfer cucumbers to a serving bowl.