Heeling is the intentional or unintentional leaning of a sailboat to one side, primarily caused by wind force pressing against the sails. It is a normal aspect of sailing, particularly when traveling upwind, but excessive heeling can reduce speed, cause steering difficulties, and necessitate crew weight management.

Key Aspects of Heeling
Cause: Wind pressure acting on the sails creates a torque that forces the boat to lean over (leeward), while the boat's weight and keel push back, creating a balanced, tilted state.

Controlled vs. Excessive: Moderate heel (often 10°–20° for cruisers) is desirable for performance, but too much reduces efficiency and may require easing sails or shifting weight to windward.

"Sail the Heel": Sailors often "sail the heel" by maintaining a consistent angle of inclination to maximize speed.

Difference from List: "Heel" is temporary and caused by wind, whereas "list" is a permanent tilt to one side, often due to improper loading or damage.

Difference from "Keel over": To "heel over" is simply to lean, while to "keel over" refers to a boat capsizing or turning turtle.