Sail Skills - Stability Free guide to ship and small vessel stability. Aimed at small vessel users but suitable for professional mariners. Diagrams, text and animations explaining stability: from righting lever to movement of liquid in tanks – the free surface effect. Demonstrates adding weights to a vessel, heel and list. Especially recommended for RYA examination candidates. Righting moment and lever A small sailing vessel heeled by the wind Diagram: relating topweight in a sailing vessel to levers and moments Levers & moments Diagram: a vessel heeled showing righting lever (GZ) A vessel recovering from inversion Inverted Stability Heel & angle of heel Diagram: a vessel kept afloat by her buoyancy Buoyancy Diagram: centre ofbuoyancy (CB) of a vessel heeling Centre of buoyancy (CB) Diagram: a vessel at the angle of vanishing stability (AVS) Angle of vanishing stability (AVS) GZ Curve for a stiff and tender vessel - showing initial steepness of curves GZ Curves Centre of gravity (CG) Diagram: centre of gravity (CG) of a vessel heeling
Every penny helps … Stability Home>Stability Explained>Heel & Angle of Heel back to top Heel & Angle of Heel A vessel is said to heel when she is not upright as the result of some force external to her. Vessels often heel when subject to wind: A small sailing vessel heeled A small sailing vessel heeled by wind Of course, waves often heel a vessel. The amount a vessel is heeled from the upright is the angle of heel A passenger vessel and a warship heeling during turn Diagram: a vessel heeled by wave action, showing angle of heel The forces required to make a turn will also heel a vessel. The sharper the turn and the greater the speed, the greater the angle of heel. Even large vessels will heel in a sharp, fast turn A vessel heeled by wave action, showing angle of heel A passenger vessel and a warship heeling during turn Diagram: a vessel heeling and a vessel listing A vessel heeling and a vessel listing The terms are similar, but not quite the same. Although not vitally important, It is worth bearing the distinction in mind when the effect on stability of load and flooding are considered
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