Just some route ideas:
Island ONLY RouteLeg 1: USA (Manhattan) --> Freeport, Bahamas
Leg 2: Freeport, Bahamas --> Galapagos Island, Ecuador
Leg 3: Galapagos Island, Ecuador --> Wellington, New Zealand
Leg 4: Queenstown, New Zealand
Leg 5: Queenstown, New Zealand --> Naha, Japan
Leg 6: Sapporo, Japan
Leg 7: Sappro, Japan --> Jaffna, Sri Lanka
Leg 8: Jaffna, Sri Lanka --> Antananarivo, Madagascar
Leg 9: Toamasina, Madagascar
Leg 10: Toamasina, Madagascar --> Manama, Bahrain
Leg 11: Manama, Bahrain --> Nicosia, Cyprus
Leg 12: Nicosia, Cyprus --> USA (Nantucket)
Land-lock Edition (Hopefully it diverse enough
)
Leg 1: USA (Las Vegas) --> Ulaanbaatar, Mongolia
Leg 2: Mandalgovi, Mongolia
Leg 3: Mandalgovi, Mongolia --> Vientiane, Laos
Leg 4: Laung Prabang, Laos
Leg 5: Laung Prabang, Laos --> Prague & Brno, Czech Republic
Leg 6: Brno, Czech Republic --> Lusaka, Zambia
Leg 7: Livingstone, Zambia
Leg 8: Livingstone, Zambia --> Geneva, Switzerland
Leg 9: Geneva, Switzerland --> Luxembourg City, Luxembourg
Leg 10: Luxembourg City, Luxembourg --> Asuncion & San Lorenzo,Paraguay
Leg 11: San Lorenzo, Paraguay --> Copacabana, Bolivia
Leg 12: Copacabana, Bolivia --> USA (Tuscon)