Ayacht ensign is aflag allowed by some nations to be hoisted as the nationalensign (instead of thecivil ensign) byyachts.
As with any othercivil ensign, the yacht ensign is the largest flag on board, and is normally flown at thestern (rear) of the ship.
Yacht ensigns differ from merchant ensigns in that their use indicates that the yacht is not carrying anycargo which requires acustoms declaration. Carrying commercial cargo on a boat with a yacht ensign is deemed to besmuggling in many jurisdictions.[1]