Advance
Shipyard
The Shipyard expands the capabilities of our port to new heights, increasing the number of vessels that can be serviced and built while also augmenting the amenities for the crew of those ships.
Advance tree
The game files don’t say where this goes: it has no requires, so the game places it in the 
Reformation tree itself.
Definitionin_game/common/advances/1_building_unlocks.txt:798
803ai_weight = {
804if = {
805limit = {
806has_ports = yes
}
808add = {
809value = 100
810multiply = num_of_ports
811divide = num_locations
}
}
}
816ai_preference_tags = {
exploration
}