In 1900 Verne wrote "Seconde Patrie", a sequel of sorts to the famous book by Rudolph Wyss. In Verne's tale two families, the Zermatts and the Wolstons, are shipwrecked on the island of New Switzerland and threatened by a tribe of savages. They explore the island and make many discoveries. Meanwhile the younger family members leave the island on the "Unicorn" headed for Europe. On their return trip from South Africa there is a mutiny on board their new ship and they and the captain are sent off in a rowboat. They eventually land on an island and soon discover it to be New Switzerland. By then the natives have taken over and there is no sign of the original colonists.

"Their Island Home" (first published in England in 1923) is actually Part One of Verne's sequel and deals with the colonist's life on the island and their explorations, as well as the family members on the "Unicorn" and their voyage. The second part, "The Castaways of the Flag" was also published by in the same year.