It is very difficult for anyone wearing wet clothes and an inflated lifejacket to board a liferaft from the water, particularly if there is no one else inside to help them. An inflatable step or ramp outside the main opening makes it much easier.
LIFERAFT SURVIVAL Pt 1: We didn’t know this would happen!
Even in these benign conditions it proved to be a much tougher exercise than we imagined. In a bucking ocean at night it would be nearly impossible, and we would soon run out of energy.