Entry & progression
Heavy weather is not survived on the day. It is survived by the preparation done twelve hours earlier, by a watchkeeper who read the forecast and believed it. On a yacht, the greatest hazard in heavy weather is not the sea. It is everything that is not tied down — including the people.
Before it arrives
- Read the forecast properly — not the app. The synoptic chart, the warnings, and the trend. Look at what the weather will do behind the front as well as in it.
- Decide early. Shelter, sea room, or a change of route — all three are cheap twelve hours out and impossible six hours in. The single most common heavy-weather error is deciding too late.
- Secure the vessel. Everything, everywhere, including the spaces nobody looks at: the galley, the laundry, the engine room stores, the crew mess, the guest cabins, and every locker in the tender garage.
- Close her up. Watertight doors, garage doors, hatches, ports, and every opening in the hull. Check them physically; do not trust an indicator lamp.
- Brief the crew and the guests. What is coming, when, what it will feel like, and where they are to be.
- Rig lifelines. Ban the weather deck. Nobody goes on deck in heavy weather without the master's permission, without a harness, and without someone knowing.
Handling her
The two things that hurt a yacht are slamming and synchronous rolling. Both are resonance problems, and the answer to both is the same: change the relationship between the vessel and the sea.
- Slow down. The most effective, most reliable, most underused action available. It reduces slamming, reduces the loads, reduces the motion, and buys thinking time. It costs nothing but arrival time.
- Alter the heading. Take the sea on the bow rather than dead ahead. Change the encounter period so the vessel is not being met at her natural roll period.
- Beware the following sea. Running before a big sea feels comfortable and is the most dangerous point of sailing there is — the vessel can broach, and a fast yacht surfing on a sea can lose her steerage entirely at the worst moment.
- Watch the free surface. Swimming pools, jacuzzis and part-full tanks turn a stable vessel into an unstable one. Empty them or press them full.
WARNING — Stability is not a feeling A yacht's stability depends on her loading condition, and on a yacht the loading condition changes constantly — fuel burnt, water made, tenders launched, a helicopter landed, twenty people on the sun deck. The vessel's stability information book is not decoration. If the vessel's motion has changed character — she has become tender, sluggish, or slow to return — that is data, and it goes to the master immediately.
The watchkeeper's part
In heavy weather the OOW's job narrows to three things: keep her safe, keep her steering, and keep the master informed. Call him. The standing orders will give you thresholds — wind, sea, visibility, motion, anything unusual — and the correct response to should I call him? is always yes.
And log it. Time, wind, sea, barometer, courses, speeds, actions taken and why. If anything is damaged, the log is the only thing that will speak for you afterwards.