Advance
Coastal Careening
Ships are undertaking longer voyages than ever before, made possible by new technical advances. This means more complex repairs are needed, but ports with adequate equipment and skilled craftsmen are not always available. Our sailors must be trained in the art of careening — deliberately beaching vessels to expose the parts that need cleaning or repair. This is the only way our fleets can maintain seaworthiness far from their home ports.
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.
Modifiers
Definitionin_game/common/advances/4_choices_mil.txt:281
283icon = rudimentary_coastal_ship_repair
284for = mil