Use a vegetable peeler to cut long, wide strips down one side of one zucchini until you reach the seeds. Turn zucchini and repeat on three remaining sides. Repeat with remaining zucchini. Discard zucchini cores.

Stack zucchini strips on top of each other, then cut thin strips lengthwise along the stack; strips will resemble spaghetti noodles.

Heat oil in a skillet over medium heat. Add zucchini "noodles" and cook for 1 minute. Add water and continue to cook until zucchini is softened and water has evaporated, 5 to 7 minutes. Season with salt and pepper.