Heavy Weather Preparation and Seaworthiness

What makes a ship seaworthy

In short: Read alarms, musters and drills first. A seaworthy ship is reasonably fit to meet the ordinary perils of the sea on the intended voyage. Not perfect: fit for this voyage, with this crew and this cargo.

• “Reasonably fit” is the test, not “unsinkable”. A ship fit for a coastal hop may be unseaworthy for an ocean crossing.
• “Ordinary perils” = the wind, sea and weather you can expect on that route and season — including a gale.
• Seaworthiness covers the hull and machinery, the people, the stability and the paperwork and procedures.

Examples of unseaworthy vessels

• A defective engine.
• A defective compass.
• Incompetent officers (not qualified or not able to do the job).
• A vessel unstable because of her cargo (badly loaded, shifted, or too high).
• A master not fully conversant with the Safety Management System (SMS).
• On the bridge: the last two surprise candidates. A ship can be mechanically perfect and still unseaworthy because of people or procedures.

Certificates and seaworthiness

• A certificate is a verifiable document: it records that the ship met a standard when surveyed.
• A valid certificate is not proof that the ship is seaworthy today — things break after the survey.
• A missing (or expired) certificate makes the vessel unseaworthy.

The 5 Cs of seaworthiness

In short: Before a voyage, the appraisal stage of passage planning (IMO Res. A.893(21)) asks one question: is this passage feasible and safe? Check it with five Cs: Construction, Condition, Crew, Cargo, Compliance.

• Construction: is the vessel built and maintained for the conditions expected? Hull integrity, watertightness, general physical state.
• Condition: are all critical systems in good working order? Engine, rigging, electronics, safety equipment. This is the operational status.
• Crew: competent, qualified, rested and properly briefed? Their skills and mental and physical state decide how safe the operation is.
• Cargo: properly loaded, secured and right for the voyage? On a yacht this also means fuel, provisions and guest management.
• Compliance: does the vessel meet legal and regulatory requirements — certificates, safety equipment, manning levels?

Compliance: what must be on board and up to date

• Certificates and documents in date.
• Nautical publications and charts up to date and relevant; charts of appropriate scale for the intended voyage.
• Sailing Directions.
• Tidal stream atlases and tide tables.
• List of Lights and List of Radio Signals.
• Weather information sources.
• Routeing guides and passage planning charts.

Heavy weather: watertight integrity

In short: Keep the sea out. Before the weather arrives, close every opening that water could find: garage door, hull openings, WT doors, hawse and spurling pipes, vent pipes.

• Start early. Use the weather forecasts and gale warnings to decide when; for a tropical storm, plan your avoiding action as well. Securing a ship that is already rolling heavily is slow and dangerous.
• Garage door closed (yachts: tender garage and other large side or stern doors).
• Hull openings closed: side scuttles, deadlights, shell doors, hatches.
• Watertight doors closed and secured — fully dogged, not just shut.
• Hawse and spurling pipe covers fitted: green water on the foredeck can flood the chain locker and the forepeak through the spurling pipes.
• Vent pipes covered: air pipes and ventilators closed or capped so water cannot run down into tanks and spaces.
• On the bridge: make a round with the bosun or chief officer and tick each item off the ship’s heavy weather checklist; log the time it was completed.

Heavy weather: vessel security and stability

In short: Let water out, keep weights still and keep the ship stiff: clear scuppers and freeing ports, extra lashings, increase GM, reduce free surface, stormboards rigged, sea valves closed except essentials.

• Scuppers and freeing ports clear: water shipped on deck must drain fast. Water trapped on deck is extra weight high up, with a big free surface.
• Extra lashings and stowage: cargo, deck gear, tenders, furniture, galley and stores. Anything that shifts can injure crew, damage the ship or give a list.
• Increase stability (GM): lower the centre of gravity, for example by ballasting low tanks and moving weights down.
• Reduce free surface to a minimum: tanks either full (pressed up) or empty, as few slack tanks as possible. Free surface reduces the effective GM.
• Stormboards rigged: storm boards or shutters over large windows and openings that a wave could break.
• All sea valves closed except the essential ones (for example engine cooling and the fire main).
• In following and quartering seas, IMO guidance to the master warns of surf-riding and broaching-to, and of synchronous and parametric rolling. Change course and speed to avoid them (IMO MSC.1/Circ.1228).

Heavy weather: crew safety

In short: Keep people off the decks, clipped on when they must go out, rested and fed: restricted access, lifelines, harnesses, liferafts checked, watch routine changed, crew rested, galley warned.

• Restrict access to open decks: announce it, and allow nobody out without the bridge knowing.
• Rig lifelines along the decks people must use.
• Safety harnesses for anyone working on deck.
• Check the liferafts: lashings, hydrostatic release, nothing that a sea can sweep away.
• Modify the watch routine: extra look-out, engine room manned, master or a second officer on the bridge as needed.
• Crew rested before the weather arrives — a storm can last days. See hours of rest and fatigue.
• Warn the galley: prepare meals in advance and secure the galley before it gets rough.
• On the bridge: in very heavy weather, tell the crew how to reach you if someone is hurt, and keep an eye on anyone who must go forward.

Steering gear tests before departure (SOLAS V/26)

In short: Mandatory under SOLAS V/26. Within 12 h before departure the crew checks and tests the steering gear. The test includes three things: full movement, visual inspection and communications.

• Why it matters: a cargo ship that loses steering in a harbour approach is a collision or a grounding waiting to happen. On a yacht the logic is the same.
• Systems tested, where fitted (SOLAS V/26.1):

1. Main steering gear.
2. Auxiliary steering gear.
3. Remote steering control systems, with their power failure alarms.
4. Steering positions on the bridge.
5. Emergency power supply.
6. Rudder angle indicators — compared with the actual rudder position.

• SOLAS also lists the steering power unit failure alarms and the automatic isolating arrangements and other automatic equipment (SOLAS V/26.1).

The three checks (SOLAS V/26.2)

• Full movement of the rudder, hard over to hard over, as the steering gear is designed to do.
• Visual inspection of the steering gear and its connecting linkage.
• Operation of the communication between the bridge and the steering gear compartment.
• Mnemonic: move it, look at it, talk to it.

Instructions on display (SOLAS V/26.3)

• Simple operating instructions with a block diagram of the change-over procedures (remote to local steering, power units) are permanently displayed on the bridge and in the steering gear compartment.
• Every officer who operates or maintains the steering gear must know the change-over procedure.

Emergency steering drills and records

In short: Emergency steering drills at least once every 3 months (SOLAS V/26.4), and every test, check and drill recorded in the log book (SOLAS V/26.6).

• A drill includes direct control from the steering gear compartment, the communication procedure with the bridge and, where fitted, the operation of the alternative power supplies.
• Ships regularly on short voyages: the flag State may waive the 12 h test; the checks are then done at least once a week (SOLAS V/26.5).
• UK ships: the dates and details go in the Official Log Book; the regulation does not apply to pleasure vessels under 150 GT (MGN 610 (M+F)).
• In areas that need special caution, run more than one steering power unit when they can work together (SOLAS V/25).
• What to do when the steering actually fails is in collision, grounding, flooding and machinery failure.