Advance
Grand Shipyard
This massive port infrastructure is a sight to behold, with innumerable vessels and sailors coming and going at any given time. Its ability to build and repair whole fleets make it a pinpoint for our expanding maritime power.
Advance tree
The game files don’t say where this goes: it has no requires, so the game places it in the 
Absolutism tree itself.
Definitionin_game/common/advances/1_building_unlocks.txt:821
826ai_weight = {
827if = {
828limit = {
829has_ports = yes
}
831add = {
832value = 100
833multiply = num_of_ports
834divide = num_locations
}
}
}
839ai_preference_tags = {
exploration
}