in 1761 ship carrying slaves shipwrecked on tromlin island. the evropean crew built their own ship out of the wreck in days and left the slaves marooned. the last surviving of them were rescued 15 years later.
how would you survive/ escape? remember, the next save shore is Madagascar, 250 miles to the east. the island itself is 200 acres and surrounded by a reef. no trees.

https://en.wikipedia.org/wiki/Tromelin_Island