Question 1

What is the Angle of Vanishing Stability (AVS) and why does it matter for offshore passage planning?

Accepted Answer

The AVS is the angle of heel beyond which the vessel's righting moment becomes negative and she will not self-right — she will capsize and remain inverted. A higher AVS (e.g. 130°+) indicates a more seaworthy vessel for offshore work; a lower AVS (90-110°) means the vessel is more vulnerable to inversion in extreme seas AVS (also called Limit of Positive Stability or LPS): the critical angle for offshore safety. CAT 1 (ocean racing/offshore) vessels typically require AVS >130°. A vessel with AVS 100° will not self-right if knocked past 100° — she remains inverted. Factors affecting AVS: ballast ratio, hull shape, cabin superstructure, deck openings. Before offshore passages, know your vessel's AVS — published in design specifications or can be measured. This is a Yachtmaster Offshore/Ocean qualification topic.

Question 2

What is heaving to and when is it used as a seamanship technique?

Accepted Answer

Heaving to: backed foresail + sheeted main + lashed helm to leeward creates a nearly stationary vessel making minimal leeway. Used for: crew rest, eating hot food, waiting for a tidal gate, reefing in heavy weather, attending to a non-urgent emergency on board Heaving to on a bermudan sloop: tack without releasing the jib sheet — the backed jib now pushes the bow away; the mainsail pushes the bow back; the balance creates very slow movement (often

Question 3

The yacht grounds on a falling tide. What are the immediate actions in the correct order?

Accepted Answer

Note the time and check the tide table (is it rising or falling?); if rising — may float off shortly, hold position. If falling — assess: heel to reduce draught (all crew to one side); deploy kedge anchor using the dinghy to deep water; motor off in reverse if possible without damaging propeller; protect against further keeling with fenders/lines to a second anchor Grounding on a falling tide: the situation will get worse for hours. Act fast. Options: 1) Motor astern immediately if just grounded; 2) Heel the vessel to reduce draught (move crew/equipment; pull the boom over and weight it; attach halyard to a kedge at an angle); 3) Lay a kedge anchor in deep water and winch off. Protect the vessel against lying on her side — rig a second anchor as a strut or prepare fenders. If she will dry out safely (flat bottom, soft ground): just wait for the flood.