You are significantly faster at loading a siege engine, as well as a better shot.
Benefit: If you are the crew lead on a siege engine, your crew can use move actions to load a siege engine. When you spend actions to aim a siege engine, you and your crew can use move actions instead of full-round actions to aim the siege engine.
Normal: Full-round actions are required to load and aim siege engines.
Pathfinder Roleplaying Game Ultimate Combat. © 2011, Paizo Publishing, LLC; Authors: Jason Bulmahn, Tim Hitchcock, Colin McComb, Rob McCreary, Jason Nelson, Stephen Radney-MacFarland, Sean K Reynolds, Owen K.C. Stephens, and Russ Taylor.