Running with following seas
Boat handling · Power & sail
Seas from astern can lift the stern, take away your steering and swing the boat broadside (a broach). Control speed so the boat stays under command, keep the stern square to steep seas and keep watching astern. Skippers disagree about drogues and other storm tactics.
Safety first
- Being caught broadside by a breaking wave can roll a boat. If a breaker is coming, the USCG's preferred answers are to get out of its way or turn in time to meet it bow-on.
- A pooping sea can sweep the cockpit. When it seems possible, keep crew clipped on and close companionway boards or doors.
- Following seas with an opposing current, as on a bar during the ebb, are especially dangerous: waves overtake you faster, steepen and break more often.
- Deploying a drogue or sea anchor in a gale puts heavy, fast-running line on deck. Keep hands and feet clear, use fair leads to strong points and keep a knife at hand.
What goes wrong
- Yawing and broaching: as a wave lifts the stern, the boat surfs down its face, the bow digs into the trough, the rudder loses grip and the stern swings. At worst the boat is thrown broadside into the trough (a broach) and can be knocked down or rolled.
- Pitchpoling: on a very steep or breaking sea the bow can dig in so hard that the boat trips end over end. The USCG notes this is rare, and that a threatened pitchpole more often turns into a broach.
- Pooping: a sea breaking over the stern and into the cockpit. It can flood the cockpit and wash people overboard.
- Stern shape matters. A wide, flat transom gives following seas more to push on than a rounded cruiser stern, and the USCG advises keeping transom-stern boats out of heavy following seas and surf.
Speed control
- In big following seas the USCG teaches riding on the back of the wave ahead, matching its speed, while watching astern for the next wave that could overtake you.
- Some boats are fast enough to stay on the back of a swell; slower displacement boats will be overtaken and have to rely on steering and timing.
- Reduce speed before a steep wave reaches you, not after it has picked up the stern. Cutting power as the stern lifts shifts weight forward and is a common way to lose control.
- Keep enough speed for the rudder to bite, and more still if a current is also behind you. On boats with trim tabs, raise them fully so they do not push the stern around.
Power and sail
- Under power, keep a hand on the throttle and steer actively. Early, steady corrections work better than a late burst of power, and slowing down or changing course can reduce yawing.
- Under sail, reduce sail before the boat starts surfing out of control (see Sailboats: reefing and heaving to). Heaving to, lying ahull and running off are all used in storms; which works depends on the boat and the seas.
Drogues: skippers differ
- A drogue is a drag device streamed astern to slow the boat and help hold the stern to the seas. The USCG boat crew handbook describes it as a way to reduce yawing and broaching.
- Opinions split sharply. Some experienced ocean sailors never use drogues or sea anchors, preferring to heave to or run off, and point to the huge loads and the danger of deploying gear in a storm. Others, especially on smaller boats, credit a drogue with saving them.
- A 1987 Coast Guard-sponsored drogue study is quoted by both sides. The Coast Guard says it recommends no particular device and that owners should choose what suits their boat. Whatever you choose must be rigged to strong points and practiced before you need it.
Sources disagree on What the 1987 Coast Guard drogue report concluded — left out rather than guessed. Check your local authority.
Sources (5)
higherlogicdownload.s3.amazonaws.com · pbo.co.uk · yachtingworld.com · para-anchor.com · sailingmagazine.net
General guidance for recreational boaters, researched from the sources listed and written in our own words. Your equipment manuals, local knowledge, the Navigation Rules and a qualified instructor come first.