Sailing along through the Micronesian Islands of the South Pacific, I got a nasty awakening this morning as I was rolled out of my bunk without warning. Fortunately I landed in  the stack below me, but the  boat was tipped over at such  an  angle that if you didn't know what  was going on  you might think the boat was about to  capsize. 

We’d been hit by another line squall; they appear to be quite prevalent in this part of the world and seem to have some teeth as well.   Once the call has been made that we are about to get hit the crew has to react quickly to make the boat safe - wind speeds in a squall can easily double or increase by 20 knots.  I could hear the guys on deck running around  as  they got the big jib down and put up a smaller sail, then  a minute  later, the reef starts to go in, I can feel the boat accelerating  and  then go quiet as the helmsman turns downwind so that the guys can make  the manoeuvre safely.  The squall has generated a sloppy wave pattern and the boat starts to crash and bump because the waves are disorganised and random. This particular squall was a real beauty and lasted about two hours.

The first indication that you are going to get nailed by a line  squall will be a general darkening and thickening of the  clouds  to  weather,  therefore if you’re reaching and you see some activity at  about 45 degrees off the windward bow, you need to start getting  prepared.    The leading edge of the squall comes with a pretty high probability of a significant wind-shift.  You will observe high black cloud above you and light rain will start to fall, this lasts for about five minutes and is generally followed by a short pause in the rain, which may be accompanied by possible clearing of the clouds.  This break will only be for a few minutes before the large drops start to fall from the puffy nimbus clouds that make up the body of the squall.

Once in the squall, the rain will be torrential, and I mean torrential.  It's really quite fun. Because the water is so cool and clean it provides  a great  chance for a shower  and generally speaking the on-deck watch has to  work around the off watch guys  streaming out of the hatch clutching   shower gel.

There's a lot of space for interpretation of both line squall theory and on the water observation.  Trust me.... everyone has his own  theory of line squall theory,  and  everybody observes  the outcome of  a  squall  in their  own  special way.

Rick Deppe MCM