You can learn how to sail through a squall before the first gust arrives. Picture a trade wind run in the Caribbean. The wind is steady at your back, with the sunset ahead. Suddenly, the sky in front of you darkens.
This guide helps you spot a squall early and prepare your boat and crew. You’ll also learn to manage the sails and wheel as the gusts hit. Finally, you’ll know what to check once it passes.
How Do You Spot a Squall Before It Hits?
You can spot a squall by its cloud, its rain, and its path toward your boat. A squall is a short burst of violent wind, often accompanied by heavy rain and a sudden shift in wind direction. Most squalls are brief, but the initial gusts can reach gale force.
Forecasts often identify a squall line, which can last several hours. If one settles over you, you'll need to know the storm sailing basics in addition to the squall routine outlined below.
Read the Cloud in Daylight
Look for a tall cloud with a flat, dark base and a gray curtain of rain beneath it. The taller the cloud and the faster it moves, the harder its gusts will hit.
If you see rain under the cloud, expect strong winds around it. A squall without rain can still throw gusts near its edges, though they're usually lighter.
Keep Watch After Dark
At night, every moonlit cloud can look like a squall. Keep two people on watch, and have them wake the skipper if they're unsure. Radar helps too, since a squall's heavy rain shows up on the screen.
Turn the radar's rain filter down or off so it doesn't hide the squall. Then check the squall's direction and distance every few minutes, the same way you'd track a ship. If the direction holds steady while the distance shrinks, it's coming for you.
If turning a few degrees takes you out of its path, make the turn. A long detour rarely pays off, since you'll likely meet another squall later. Before dark, check the radar layer in your weather and navigation apps to see where squalls are lining up.
How to Prepare Your Boat and Crew for a Squall
Learning how to sail through a squall starts with prep. Run the same routine every time so each crew member knows their job without a long briefing.
Run a Fast Squall Prep Checklist
Start this list as soon as you spot a squall heading your way. Split the jobs among the crew so they happen at the same time.
Life jacket and harness: Everyone puts on a personal flotation device (PFD) and a harness.
Jacklines and tethers: Rig jacklines along the deck, and clip on before you leave the cockpit.
Foul weather gear: Put it on before the rain hits. Even in the tropics, a soaked crew gets cold fast.
Hatches and ports: Close and latch them, then slide the washboards into place across the cabin entrance.
Loose gear: Stow it below, or tie it down on deck.
Lines and halyards: Coil them so they run free when you reef.
Jib furling line: Check that it's wrapped evenly on the drum so the jib won't jam.
Once the crew finishes the list, everyone clips on in the cockpit. From there, you wait for the skipper's call to reef.
Pick a Safe Location and Ready the Engine
Plot your position and mark nearby hazards like rocks, lee shores, and shallower water along the coast. Your berth or mooring is the safest place to ride out a squall. Open water with plenty of room around you comes next.
The worst place is near home, in a narrow channel or harbor. Fishing boats and cruisers crowd in, and you'll have little room to turn.
Start the engine and leave it in neutral. If a sail jams, you can motor with the bow pointed into the wind and drop it.
How to Sail Through a Squall as Conditions Worsen
Adjust the sails in this order as the wind increases. Then, concentrate on steering.
Reef the Main at the First Sign of Rising Wind
Sailors have an old rule for squally weather. If you're asking yourself whether to reef, reef now.
Tuck a deep reef in the mainsail at the first sign of rising wind. On many boats, the spreaders on the mast angle backward. When you sail far downwind, the main presses against them and won't slide down.
Reefing in a squall may mean turning into the wind and waves. Reef early to avoid that maneuver. Our tips on boat handling in high winds guide you through reef setup step by step.
Furl the Jib at the First Gust
When the first gust hits, roll the jib all the way in. Ease the jib sheet as you pull the furling line. Keep a couple of wraps on the winch so the sail rolls in tight.
Sailing downwind with the jib held out on a pole? You can furl the jib and leave the pole in place, as long as the lines hold the pole steady.
Take Down or Blow the Spinnaker
Take the spinnaker down well before the squall arrives. A snuffer, a long sock you pull down over the sail, makes this faster. At night, keep the spinnaker in its bag whenever squalls are around.
Did the squall catch you with the spinnaker up? A skilled helmsperson can often keep it flying through the gusts. A rushed takedown in a squall is risky without a practiced crew.
If the load becomes too great, blow the spinnaker. Let go of every line that holds it, halyard included, so the sail spills its wind.
Steer to the Wind Angle
Put your best helmsperson on the wheel, or set the autopilot to steer by wind angle. On a compass course, the autopilot holds its heading as the wind shifts. If the wind swings behind the main, the boom can slam over in an accidental gybe.
Hold the same angle to the wind, even if your heading swings far off course. Skip any gybe to match the new wind, since the trade wind returns once the squall passes.
On a downwind course, rig a preventer before the squall arrives. Run this line from the end of the boom forward to the bow, then back to the cockpit. Show the crew how to release it at night.
What to Do After the Squall Passes
Even after the rain stops, the back of a squall can bring a second round of gusts. Keep your reefs in until the low, ragged clouds overhead break apart.
Use that time to check the boat. Look in the bilge for water from hatches or hull fittings. Inspect the shrouds and blocks for damage, and check every line for wear.
Next, check each crew member for injuries, chills, and seasickness. Hand out dry clothes, warm drinks, and food. Once the sky opens up and everyone's warm, shake out the reefs and unroll the jib.
Practice Squall Drills at Sea With Sailing Virgins
Practice your squall drill on calm days. Time how fast your crew can reef and furl. Sailing Virgins offers offshore and advanced courses. You can practice these drills at sea with experienced captains who have crossed oceans.
Our advanced course earns you the ASA 105 and 106 certifications. You'll need ASA 104 to join.
You'll train in night passages, watch schedules, and reefing in heavy weather. You'll also learn to read weather forecasts at sea. You'll decide when to reef, dodge, or hold course.
Want to practice sailing through a squall with an expert beside you? Book your advanced course with Sailing Virgins and take the wheel on your next passage.