A sudden marked increase in wind speed often bringing rain or low lying cloud cover, they are the spookiest part of sailing in the tropics where the temperature of the sea creates massive amounts of moisture in the local atmosphere and huge pressure gradients over small areas. This result is intense local winds that can accelerate in speed in seconds flat. I’ve seen 5kts of wind turn into 40 in 30 seconds – hardly enough time to drop the main and furl the genoa. One must be exceedingly vigilant in the tropics, especially at night and even more so when there is no moon out. As a delivery skipper who has sailed hundreds of thousands of miles, even though my yacht delivery company is based in Cape Town, many of my deliveries are in and around the tropics. During these parts of my journey I sail with even more caution than I would in cooler areas.
Luckily, squalls do not come without some telltales to warn of their approach. The obvious indicator, when visibility allows it, are clouds that seem to sit on the water itself where the clouds surrounding it do not, this is moisture or rain and can appear in a range of colours from white to almost black. They are often typified by massive, high reaching cumulonimbus clouds above them. In the correct light you should be able to gauge the accompanying wind speed by the angle at which the curtain of rain is falling. Big angle = big wind. When light and the moon fail, you’ll need to use your other senses to detect other tell-tales. I find the order of events to be as follows – although not all the tell tales may be present.
Slackening of the wind – A powerful squall will suck the wind out of the surrounding area, leaving you windlass until it’s on your doorstep.
Change in wind direction – If you do have wind prior to the squall’s arriving and experience an unprecedented shift in its direction then a squall is close but may not necessarily hit you. If there is large and sudden shift in wind direction then you are about to be hit.
A drop in temperature – A powerful squall bringing strong winds with it will usually drop the air temperature by a noticeable degree. The bigger the drop in temperature and the more suddenly this occurs, the stronger the squall.
The Smell of Rain – If you catch a whiff of sharp, clean, chlorine-like air then a squall is about to hit you and it’s going to bring rain – lots of it!
Drizzle – Your final warning leaving you just seconds. If you haven’t dropped sail by now then I suggest you get a move on! Sometimes the wind will hit you before the rain or simultaneously, in which case you’re already too late. You may not even have rain at all; therefore, this is not a reliable indicator.
Getting Caught With Your Skirt Down
Spilling the Main – Your first line of defence at a sudden increase in wind strength is to spill the mainsail by easing out the mainsheet. However, if your mainsail is already as far out as it can go (as in already touching the shrouds) – in the case of a broad reach or run (or in the case of a catamaran, on the beam) – then move to your next line of defence..
Heading Off – Head off the wind. You can do this if the wind is in any position forward of a deep broad reach, but if you are already running or close to it then you won’t be able to head off any further.
How to: use the autopilot by pressing the 10 degree button a few times in succession but not so much so that you jibe the mainsail. In other words, if your apparent wind angle is 120 degrees to starboard then you can comfortably go 40 degrees to port by pressing the 10 degree button 4 times in succession, leaving 20 degrees between the stern angle and the apparent wind angle to prevent jibing. Bear in mind that a sudden and acute angled course change off the wind, when the wind is already quite far aft of the beam, will exacerbate the jibe potential if you are entering the trough of a swell, so don’t be too aggressive. In the above example press 10 degrees 4 times in quick succession followed immediately by 10 degrees to starboard so that the autopilot can begin countering for the overturn. Then when the course is stable go another 10 to port, giving you your 40 degrees.
Pre-emptive action
Acting more pre-emptively with a visual sighting of the squall still a safe distance away, put a reef in the genoa and with a more certain estimation of the squalls strength as it approaches determine whether you think you can ride it out by heading off, spilling the main and/reefing the genoa or whether you need to put a reef in the main. This isn’t easy to tell, especially for the inexperienced so if you’re not sure, rather err on the safe side and put the reef in.
Bear in mind that the wind direction you are experiencing prior to the squalls arrival may not be the wind direction you experience upon its arrival. Wherever the squall is coming from is where the wind will come from. If for example you are sailing on a broad reach and with the squall’s approach the wind moves forward to the beam, this advantageous as you now have a greater range of angle within which you can head off and reduce the wind speed. Whereas if the squall comes from aft or bends the wind aft you have a reduced scope within which to head off and reduce wind speed. Factor this in when determining whether to reef or ride a squall out.
If the squall looks particularly mean and approaching faster than expected, then instead of putting a reef in, drop the whole main in a hurry. Put your reef in once it has passed.
Being squall ready
There is a sequence of many tasks to perform when shortening sail, but this number can be reduced before crunch time by having certain stops in place prior to the shit hitting the fan.
- If the excess of your mainsail preventer is coiled and hanging on the lifeline, uncoil it and dump it in the cockpit.
- Have your genoa control line on the winch and ready to wind.
- Have your genoa sheet tensioned on a winch with the spinlock on the open position.
- If your main halyard has a spinlock on the mast as well as one at the helm then keep the mast one in the open position.
- Remove the main halyard from the rope bag and dump it tail first on the cockpit floor.
- Uncoil the topping lift and leave it on deck.
- Have all forward facing hatches closed.
- Have your rain jacket at hand, if not already on and keep your headlamp close by.
Written by Jason Ruger