Используйте «low-water mark» в предложении

1. That was the low-water mark of his presents, and, if her cousin was right, the high-water mark of his single-minded devotion

2. No other company was in the house than the landlord, his wife, and a grizzled male creature, the "Jack" of the little causeway, who was as slimy and smeary as if he had been low-water mark too

3. this time the river slowly rises until it attains a height of nearly forty feet above its low-water mark