2.8 Heavy Weather Deck Handling
Key Takeaways
- Broaching is loss of directional control that leaves the vessel broadside (or nearly so) to the seas; pitchpoling is an end-over-end pitch through the vertical.
- When laboring off a lee shore, put the sea and wind about two points on either bow and reduce speed as needed—do not lie in the trough or charge full power into every sea.
- If the propeller races when the stern lifts, decrease engine speed to limit shaft and machinery damage.
- A vessel drifting with high superstructure forward tends to lie with the wind coming from abaft the beam.
- Liferaft launching requires a clear, correct side, painter secured as designed, inflation/release per type, and accounting for wind, sea, and passenger control—never a casual throw-over.
Heavy Weather Is Deck General and Survival Seamanship
Q160 (and related safety modules) expect a Master LT 100 candidate to choose the right attitude and speed when the sea turns ugly, to protect machinery when the screw comes out of the water, and to understand how a high-sided passenger vessel will lie when drifting. This section is pure command judgment: the same choices you make on a whale-watch return in a rising northwest gale.
Broach vs Pitchpole
Broaching
A broach (or broaching-to) is a loss of directional control in which the vessel is forced broadside (or nearly broadside) to the waves—often from a following or quartering sea that yaws the stern and trips the hull. The vessel may heel violently, ship water on deck, and, in extreme cases, capsize. Quartering seas are a classic broach setup for small passenger craft that run home too fast with the sea on the quarter.
Prevention cues: reduce speed, adjust course so the sea is not driving the stern around, and restore steerage before the yaw becomes uncontrollable.
Pitchpoling
A pitchpole is an end-over-end evolution: the bow digs in, the stern is thrown over, and the vessel pitches through the vertical. It is associated with very steep seas, excessive speed down-sea, or designs that bury the bow. Pitchpoling is rarer in exam stems than broaching but is the contrast answer when the question describes end-over-end motion rather than yawing beam-to.
| Term | Motion | Typical setup |
|---|---|---|
| Broach | Yaw / beam-to the seas; loss of steering control | Following or quartering seas, too much speed |
| Pitchpole | End-over-end pitch | Steep seas, bow digs, stern thrown over |
Do not use the words interchangeably on Q160. If the stem says the stern is kicked around and the vessel ends up in the trough, think broach. If it describes cartwheeling bow-over-stern, think pitchpole.
Laboring Off a Lee Shore
A lee shore is a shoreline downwind (and usually down-sea) of the vessel—the shore onto which wind and sea are setting you. Laboring off a lee shore with insufficient sea room is a classic disaster scenario: every minute of leeway costs water depth and options.
The standard handling answer
When the vessel is laboring in heavy weather off a lee shore, the generally recommended handling is to put the sea and wind about two points on either bow and reduce speed as needed. "Two points" means roughly 22.5° off the bow—not dead into the sea at full power, and not broadside in the trough.
| Choice | Why it is right or wrong |
|---|---|
| Sea/wind ~2 points on either bow + reduce speed | Maintains control, eases pounding, limits leeway growth better than lying beam-on |
| Full power straight into every sea | Increases slamming, structural loads, green water, and injury risk |
| Lie broadside in the trough | Maximum roll, shipping water, loss of ability to claw off |
| Seas directly astern at high speed | Broach and pitchpole risk; may set you faster onto the lee shore if control is lost |
The goal is to claw off or hold position safely until the weather eases or you reach a harbor of refuge—without breaking the boat or injuring passengers. Speed reduction is not optional decoration; it is part of the correct answer pair with the bow-angle attitude.
Propeller Racing
In large seas the stern lifts, the propeller breaks free or partly free of solid water, and RPM spikes. That is propeller racing. Unchecked racing pounds the shaft, reduction gear, and engine with sudden load changes when the screw bites again.
Immediate response taught for exams and good engineering practice: decrease engine speed (throttle back) so the propeller cannot overspeed when it ventilates, then restore power smoothly when the screw is back in solid water. Standing orders on many small passenger vessels explicitly require the watch to ease throttles in racing conditions rather than "power through" every crest.
Related habits: avoid unnecessary large throttle swings in confused seas; secure loose gear; keep passengers seated and off weather decks when shipping seas.
Drifting Attitude and Superstructure
When a vessel is drifting (engines not making way, or unable to), wind on the superstructure often dominates heading more than underwater hull form. A vessel with significant superstructure forward (pilothouse, passenger cabin, high bow structure) tends to weathervane so the wind comes from abaft the beam—the heavier windage forward is blown downwind, leaving the vessel lying with the wind more from aft of abeam.
Exam phrasing to recognize: "drifting with superstructure forward — tend to lie with the wind from abaft the beam." The opposite extreme (heavy windage aft) would tend to put the wind forward of the beam. Use the actual superstructure distribution in the stem if given; the Master 100 stock fact is the forward superstructure → wind abaft the beam pattern.
Launching Liferafts — Considerations
Heavy weather and abandon-ship situations turn liferaft launching into a command sequence, not a casual deck chore. Considerations repeatedly emphasized for small passenger (T-boat) masters:
- Right raft, right station: use the embarkation point and raft assigned in the station bill; keep painters and hydrostatic releases configured as designed.
- Painter made fast before the raft goes over so the inflated raft does not blow away from the vessel.
- Launch to leeward when possible so the raft inflates in the lee and boarding is less likely to pin people between raft and hull—or follow the vessel-specific procedure if it differs for good reason.
- Clear the water of debris, lines, and props; account for list and sea state so the raft does not inflate under the counter or into the screw.
- Inflation and boarding order: inflate as designed (manual pull or automatic as equipped), board weak persons and passengers in lifejackets under crew control, keep a knife ready for painter cutoff only when clear of the sinking vessel and as trained.
- Do not inflate on deck unless the procedure and space truly allow it; a deck-inflated raft can block escape or go over the side uncontrolled.
- Passenger control: muster, headcount, and lifejacket discipline before and during launch prevent the chaos that loses people alongside in cold water.
Liferaft details also appear in Deck Safety chapters; for this heavy-weather handling section, remember that launch discipline is part of deck handling under stress—wind, sea, and list change every step.
Worked command picture
Evening return, steep quartering seas, passengers standing for photos. The stern starts to yaw—you recognize broach onset, slow down, and bring the sea more onto the quarter-bow rather than deep on the quarter. Off a rocky lee shore with the vessel laboring, you settle on wind and sea about two points on the bow at reduced RPM, not a beam-on drift. When the screw races on the crests, you ease the throttle. If you must abandon later, rafts go with painters fast, to the best lee, under crew control—not free-thrown into the dark.
Exam framing for Q160
Highest-yield lines: broach = beam-to / loss of steering in following or quartering seas; pitchpole = end-over-end; lee shore laboring = ~two points on the bow + reduce speed; prop racing = decrease engine speed; forward superstructure when drifting → wind from abaft the beam; liferafts = painter, lee, clear water, passenger control. Those phrases are the stock answers Coast Guard item writers reuse for a reason—they match real survival seamanship on small passenger vessels.
Running in large quartering seas creates what steering risk that can lead to loss of control or capsize?
Your vessel is off a lee shore in heavy weather and beginning to labor. What handling action is generally recommended?
When the stern lifts in a seaway and the propeller races, what should you do?