1. Wash the cucumber, trim each end and score the length of the cucumber with a fork. Slice thinly, place in a bowl and sprinkle with the salt.
2. Allow to stand for about an hour so that the juices are released from the cucumber.
3. Drain well, pressing with a saucer to remove excess liquid.
4. Make up the dressing with the water, vinegar, sugar and pepper. Mix well.
5. Pour over the cucumber and allow to chill before serving. Sprinkle with chopped fresh dill, if used.