1) Deepwater rice is able to withstand water levels of 50-100cm or higher through adaptations like stem elongation, nodal root growth, and "kneeing" to keep reproductive parts above water. 2) Popular deepwater rice varieties include Swarna Sub1, Sudha, Jalmagna, and Hangeswar which show tolerance to flooding depths of 100cm or less. 3) Deepwater rice employs two strategies - escape through stem elongation or quiescence through stunted growth - to survive prolonged flooding periods by accessing air or saving energy respectively.