Monday, October 10, 2005

Sometimes radar just doesn’t see the big stuff. I was sailing with my brother John and my nephew Kevin several years ago, on John’s lovely boat Southern Cross, a 45-ft Ocean Cruising Yacht. We had this idea to sail up the Strait of Juan de Fuca just for the hell of it. Most people in sailboats just cross it and try to stay out of its way. The strait is one of the busiest shipping areas in the world. The fairways in bound and out bound are under U.S. Coast Guard vessel traffic control, and often stack up with super tankers, container ships, tugs with tows as well as pleasure boats like Southern Cross. So we have worked our way up the strait, tacking continuously. It is blowing 15 – 25 knots and we are rushing through a wet dripping blanket of pea soup fog. I am on the helm and Kevin is working the sheets for me. John is below navigating and watching the radar screen as he tracks the positions of ships around us.

The logistics of big ship radar is such that they can’t see us at all. The radar reflector on Southern Cross is maybe 40 feet above the water; most of these ships have their decks higher than that and their radomes are on masts much higher still. It order for them to see us we would have to be 20 or more miles away. In the close confines of the strait we are invisible in this fog. On the other hand, our radome is about 12 feet off the water and we should be able to see everything, and do, as John sings out sightings up the companionway, and Kev and I alter course in response. When a big ship gets close you hear it and feel it; no fog horn is necessary. The ship’s props send out whomp whomp whomps you hear across the water. As the ship gets closer you begin to feel that same whomp of the screws tingle your feet in the cockpit. And, when the ship gets very close you hear the bow pushing tons of water aside.

We have sailed this way for a night and most of a day, tacking back and forth across the strait, enveloped in a silent cocoon of fog, surrounded by distant moans of fog horns, dodging ships the size of buildings that we never see except as blips on the screen. The wind funnels down the strait from the Pacific and the tides have not been in our favor. John occasionally calls out the shore or a known marker on the shore, and an occasional fog horn from a light house, sharply decreasing depth on the depth meter, or in some cases the sound of surf against the shore confirms his analysis of the radar screen. Yet he is absent in telling me about a ship I can begin to hear…that whomp, whomp, whomp of her screws. I call down the companionway, asking him to double check. No nothing, he says after a moment.

Fog defuses sound vibrations and the ship could be anywhere. I call down to John again: “I’ve got a ship close by….anything?” Kevin’s eyes get big. Another pause from John and then the all clear again. The sound becomes stronger and more defined. She is probably steaming at 10 or more knots—they are so big then look from a distance like they’re hardly moving and their speed can be deceiving. Kevin looks more nervous so I ask him to go below and ask his dad again. He flies down the companionway. He’s back up in two seconds saying there’s still no sign of a ship close to us on radar. Since we are sailing at about 7 knots I assume we aren’t heading bow to bow (a closing speed of easily 17 to 25 knots) since the sound isn’t increasing that rapidly; yet I can now feel the vibration of her props through the sole of the cockpit. I know she’s gaining on us, probably from behind, doing easily twice our speed.
Another check with the navigator is the same: all clear, nothing near. Kevin is going to hurt his neck trying to look everywhere at once.

Now I just barely detect the sound of her bow wave, sort of a waterfall sound easing through the fog. She’s close and definitely behind us. The trouble is I don’t know if she has seen us and is turning—takes a while in something that big—and if I change course I could run into her. On the other hand I don’t think the skipper knows I’m ahead or he would have turned sooner.

I ask Kevin to dig out the Freon-charged air horn. He dives into a cockpit locker and shoves an old rusty thing at me. I fire off 5 anemic blasts close together; the universal distress alert. The fifth blast sounds more like a duck quaking as the canister runs out of Freon.

The sound of the bow through the water is very distinct and constant now, close enough to know the exact location of her behind us. I calmly ask Kevin to find me a spare can for the horn. He jumps down the companionway and reappears almost instantly with another can. I screw it in place and fire off another 5-blast warning. The waterfall sound is louder and growing at a quick steady pace. I have a fleeting thought of accounts of sailors in small boats who have been hit by passing ships and reported that usually the force of the bow wave had pushed their sailboat up and to one or the other side before actual impact. I wonder if John’s boat, at 20-thousand pounds, is still small and light enough to be affected by the bow wave, or if we will get sliced from stern to bow like a buzz saw.

Kevin is nervous as a cat and John STILL sees nothing, but the horn blasts take affect. I can detect a change in direction to the bow wave, now beginning to move across our stern to port and the deeper middle of the channel. I see nothing, but hear the waterfall of her bow wave, the throbbing of her engines, the whompping of her props. A minute later her wake gives us a little surfing push as we sail on in this thick white swirling cloud.