The chase guns, usually distinguished as bow chasers and stern chasers (or just chasers for short) were cannons mounted in the bow or stern of a sailing ship. They were used to attempt to slow down a ship either pursuing or being pursued, typically by damaging the rigging and thereby causing the target to lose performance.

Bow chasers might be regular guns brought up from the gundeck and aimed through specially cut_out ports on either side of the bowsprit, or dedicated weapons made with an unusually long bore and a relatively light ball, and mounted in the bow. Stern chasers could also be improvised, or left permanently in the cabins at the stern, covered up and used as part of the furniture.

In the age of sail, shiphandling had been brought to a high art, and chases frequently lasted for hours or sometimes days, as each crew fine-tuned their sails to take advantage of small variations in the wind. A single lucky shot could cut through a critical line, or cause a sail to split if the wind was strong, so if the ships were within range, the best gunners on each would use their chasers to make carefully aimed and timed shots at the other.