How do you re-board a yacht if no-one lowers the boat ladder?

Suppose you take a boat into the middle of the ocean, go for a dip (or gets washed overboard by a wave, or stumbles, or gets thrown overboard) but forgot to lower the boat ladder. No-one is on available to help you on-board. The hull is too slick to climb up, and the deck is too high above the water. This has to happen and there has to be an easy way to get back on-board. In such a situation, how can a person re-board without the ladder?