Saturday, April 21, 2012

Squall Country: Welcome to the ITCZ

We knew we were approaching the ITCZ (Intertropical Convergence Zone), an area marked by squalls, high electrical activity, and the doldrums (calms). The ITCZ is found anywhere from ten degrees North of the equator to ten degrees South, but at this time of year is more typically found between 03N and 07N. Its boundaries are constantly shifting, and the wily ITCZ can move location, split into two zones, or dissipate on a daily basis. This is why such an important---and difficult--- part of planning for cruisers headed to the South Pacific or Galapagos is to determine at what point one will cross the ITCZ and try to minimize the boat's time spent there. Most people try to cut across the ITCZ at ninety degrees, taking the shortest distance across it; however, since the zone is not fixed, this can be a crap shoot. In our case, the zone had temporarily shifted up to 10N.

We had seen the precursors to ITCZ-type squalls---or perhaps actually experienced some squalls that weren't bearing huge amounts of wind---during the past several days. This morning, however, we experienced our first squall at full force.

Patrick and I always seem to do things the hard way. On our first extended sailing trip together, we didn't have time to circumnavigate Vancouver Island, so instead, we went up the west coast of Vancouver Island. The weather was fair, so I wouldn't exactly say that we "battled" winds and currents the whole way, but they did impede our progress. After her purchase, we brought Silhouette up the coast from San Francisco to Seattle, again beating or motoring against northerlies the entire way. We were on a schedule because I had to be back to work by a certain date, so the entire trip was made to weather. (It wasn't until we left Neah Bay and made our big left turn that we first experienced downwind sailing on Silhouette.) Now, we find ourselves headed for the Galapagos in a cruising season marked by uncharacteristic light airs and calms---and up until now, a distinct absence of trade winds---adding an extra 1600 miles to the 3000 mile journey to French Polynesia. Nope, we never seem to do things the easy way.

It was the same with our first squall.

"I need your help." Patrick's voice woke me from the pilot berth to which I'd only retired an hour before. "One of these things is bearing down on us, and I'm not sure what it's going to do." I hastened into the cockpit.

Patrick had been using radar to dodge the storm clouds and squalls. Rain shows up on the radar like an inky Rorschach test, allowing one to navigate away from potential squalls. Patrick thought he had successfully left this one behind, but the squall had suddenly changed direction and was almost upon him. We had up a full main and headsail. It was too late to reef. We furled the headsail to reduce sail quickly. Unfortunately, the stopper knot had worked itself out of the end of the sheet without either of us noticing, and we lost the end of the working sheet through the block. We had to furl up the entire working sheet to keep it under control, and that lost us valuable time. We were lucky that the sheet didn't get tangled in the rigging.

Patrick had been steering with one hand, while tailing the furling line for me with the other, leaving me free to use both hands to grind the winch. All the while, the wind was quickly building. By the time we finished furling the headsail, Patrick needed to use both hands for the helm.

I moved to the traveler as the sky released a torrent of rain on us. There was already too much pressure on the sail to be able to pull the traveler up on center in a controlled manner. We gave up on that idea and instead, I sheeted in the main sheet as much as possible. By this time, the wind had reached the maximum force that one expects to see in a squall: 35 knots. I had my life vest on but realized I wasn't clipped in. I clipped in, then, I clipped Patrick in as he stood braced at the helm. Silhouette was heeled far over, but amazingly, her rail was not yet in the water, even with the full main up. Furling the headsail had been just enough. The sea state had been transformed into something resembling a storm, as slate gray waves frothing with white caps raced away from us in the driving rain. The waves weren't the height of actual storm waves, however; due to their limited fetch. At some point, there was a brilliant flash of lightening, followed by Crack! and a thundering Ba-boom! a fraction of a second later. The lightening was very close. I don't know how many minutes the squall lasted---only a few---but as the wind started to ease, Silhouette righted herself. It took us slightly longer to leave the rain behind.

We had fishing lines in the water at the time. That morning had started with Silhouette being surrounded by a huge school of dolphin in feeding mode. I had wasted no time in getting my lines in the water. Now, we hauled in the lines in order to start the engine. The line with my tuna feather on a wire leader attached to 60 lb test line had broken off, and the lure was gone. At some point while Patrick was outrunning the storm, we had lost a very big fish. Dang! In an ocean full of fish, it's a lot harder to catch one than you'd think! We motored our way out of the trailing edge of the squall.

After a hot breakfast during which our nerves recovered, we freed the tangle of sheets wrapped around the headsail and resumed sailing. This time, we put in a double-reefed main. We spent the rest of the morning and early afternoon sailing through squalls, but we only had to work hard to out-maneuver one of them. The remainder of the time we spent mesmerized by the horizon, watching the pageantry of squalls moving across the sky. A squall looks like a particularly dark thundercloud---the kind that is about to unleash buckets of rain on you---and can be miles wide. In the case of a squall, you can actually see the rain falling in a thick, slate-gray curtain---the antithesis of a spotlight--- reaching from the clouds in the wings to the dramatic stage of the sea's surface, a vertical column of impending chaos. As the squall advances, it sends out its vanguards in waves, moving ahead of the potent wind in the brooding veil of rain.

Late afternoon clearing allowed us to shake the reef out of the sail, but as evening fell, we played it safe and put a reef back in, even though we paid a penalty in a reduction of speed. Several boats ahead of us had written of the "towering cumulus" they observed accompanying some of these squalls. In the evening, I saw just such a tower. The cloud pillar reminded me of the famous image from the Hubble Telescope: "Birth of the Orion Nebula."

I had first watch and checked the radar frequently, but we seemed to be on a course where the ominous dark clouds were passing over us before they reached squall force. We had seen that happen once or twice before darkness fell, when we felt a brief increase in wind as a dark cloud passed over us, but didn't see the shade drawn by the rain upon the horizon until the cloud was well past us. About halfway through my watch, we appeared to sail out under the last of the dark clouds and into a clear sky opening up with stars.

Some spirit dolphins came to join the boat. In the current calm sea state (we were sailing quietly along at two to three knots), I could see the individual particles of bioluminescence in their wakes instead of the usual ghostly silver trails. They looked like so many Milky Ways in the galaxy of ocean.

By the time Patrick took his watch, we had been clear of the squalls for about two hours, so I watched him shake the reef out of the main before I went below. No doubt many more squalls stand between us and French Polynesia, but having been through our first one, we hope to be better prepared for the ones that lie ahead.

Posted at sea via ham Radio.

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