Try this one...
Rome-14
In this Rome's history
Caligula was obsessed from Childhood about boats, ships, and the sea.
Tiberius found out about this when Caligula was 14. He then sent the boy to
Hispania Baetica to study shipbuilding and sailing. Caligula became very good at both. When Tiberius ( who in this world decided that he's make
Claudius emperor, because he thought him a fool) died and Caligula went to Rome to see Claudius made emperor, Caligula asked Claudius for the resources to explore the seas.
Claudius thought that would keep Caligula busy so he set him up.
It is now the year 1,000
AUC. Rome is settling the Caribbean and making regular trips to Asia.
Basically, Roman plus the Age of Sail.