A PERSONAL NOTE

I have a "thing" about organizations with out-of-date websites. But I'm quite fond of one such organization to which I belong; The Tiddly Cove Yacht Club. Sooooooo, either stomp and scream, or leave the club, or fix it. The latter being, of course, the more productive of these choices. Our editor simply finds that his life, at present, is not consistent with getting the Winks publshed and I do have plenty of experience from past years of editing our newsletter. This is not easy: I feel out of touch. We missed the January meeting because Leila and I were searching an uncle that she had never met, in a remote village in China, and the February meeting because we were meeting some of her old classmates from Laos, in San Francisco. (She sure is social!) This issue will be in just about any order, and won't even take time for the spell-check, since I'm going to gather information and write as soon as I can. Hereafter, assuming I get enough help and encouragement to do further issues, I will beg submissions from any source, and "close" on the first day of each month, and plan to forward an issue to our webmaster by the 10th of each month. First off, I will put in an article about tides that I submitted in January, and never got published. Then I will add an article I wrote VARC for publication in some professional journal, but which --well, let's simply say, it didn't. (Update ­- article was sent to Boat Journal so I'll leave it out).

Ernie Fiedler

ABOUT TIDES

We sailors live by tides. It pays to understand them, if only to enjoy. First it must be said that nobody understands tides completely. Some tidal phenomena remain mysteries. Furthermore, I will cheat a little on details, in order to make it as simple as possible.

Last month I challenged readers to explain the second high (or low) that happens each day in Vancouver. (If the Winks had been published)

The earth's tides amount to two bulges in the earth's oceans. One bulge is toward the moon, with a certain "time lag" resulting from resistances such as land masses and the other is opposite the moon. This is because as the moon circles around the earth, it in return, moves the earth. The earth-moon system rotates around a center of mass (gravity if you choose) which is not at the center of the earth, but rather is 1700 km below the earth's surface at a point toward the moon. So the as the moon is "flung around the earth", the earth is, to a lesser extent, "flung around the moon" thus there is a centrifical force pulling the earth's water away from the moon accounting for the other bulge. (Another acceptable explanation would be to point out that the side of the earth away from the moon is farther from this center of mass/gravity/rotation). It would not be wrong to say that one tide is when the water is pulled away from the earth, and the other is when the earth is pulled away from the water.

But the sun also effects the tides, with a force of between 1/3 & 1/2 that of the moon. Therefore, the extreme tides happen when the forces of moon and sun are in alignment - either on opposite sides of our planet (full moon condition), or together on the same side of our planet (new moon condition). These are called "spring tides" (nothing to do with seasons!). When they are out of alignment, -sun and moon at right angles, the tides are less, and we call them "neap tides" They happen in two-week cycles, since it is two weeks from new moon to full moon. If tides are big today, I know that a week from today they will be much less. Nice to understand for those of you that dig clams.

There are two, or actually three basic tide patterns to be found. Diurnal tides, are tides of one high per day, and one low per day. Semidiurnal tides have two highs and two lows per day. The third category is a mixture of the two, and that's what we have in the Strait of Georgia and Vancouver. We have a few days each two-week cycle that come close to diurnal, and a few that come close to semidiurnal, but mostly mixed. Victoria, on the other hand, has more of a diurnal pattern. How can this be? An explanation requires a bit of "wave theory". The same wave features can be found in water waves, sound waves (including the air column in any wind instrument, or the strings of a string instrument), or a jump rope, our most useful example. What needs to be understood is what a node is. You have probably seen a jump rope turned in two segments, while the middle essentially stands still. This point of no or minimal motion is a node. Most waves are complex, so for example, a violin string oscillates in one segment, two segments, four segments etc. all at the same time. Complicated? Well that's how the tides are too.

The bulges that the moon pulls around the earth are only a meter or less in height. Our tides of fifteen feet are the result of this bulge piling up against the land. So we have to view the tidal waves (tsunamis are not tidal waves) as periodic waves that pile against the land, and surge back to sea, meeting the next incoming tidal wave. As they meet there will be a node developed, and - they tend to meet at Victoria. But also, the Georgia Strait is to some extent a node also, which accounts for the fact that tides for the entire strait can be predicted from Point Atkinson. It all rises and falls together.

PREDICTING TIDES IN VANCOUVER

We only need to know where the moon is, to know time of the high tides, since this bulge follows the moon. Do add four hours though for it to get into the Strait of Georgia! Why four hours? Well, because four hours are required for the water to make it's way in from the open sea to Vancouver. For example, take the new moon of December 23 2003. I choose the new moon, because the moon and sun are pulling together, and it makes the most distinct bulge/tide. On that day, the high tide prediction for Tofino was 11:54 - almost perfectly in the middle of the day, when both the sun and moon are at the zenith, (exactly south). That high reached Esquimalt at 12:42, Sidney at 14:03, and Vancouver at Point Atkinson at 15:50 (Deep Cove 16:18).

So if you want to know what the tide is, and can't see the moon, you only have to know when it was "new" or "full". The moon is toward the sun at new moon, and drops back about 13¡, or about an hour per day. The same applies at full moon, consider the moon as dropping back from this sun-moon alignment, and figure the tides accordingly. If more than a week after the new or full moon, figure toward the next new/full moon - and don't forget to add four hours -or go sail somewhere around Tofino.

TIDAL CURRENTS

More useful than tide, from a sailing perspective, is the current. Simple minded logic would say the current would "come in" when the tide rises, and "go out when it falls" and that spring tides will carry big current, and small tides will carry little currents. To quote Ira Gershwin's Porgy and Bess: "It ain't necessarily so" (How many times have you seen the tide rushingout past the Pt Grey Bellbuoy??) There are both simple and complicated reasons for this.

Reason 1. Let's imagine for a minute, a tidal lagoon, with a very restricted entrance (or you can imagine Porpoise Bay inside the Skookumchuck Rapids). The tide comes up, but the lagoon cannot fill that fast, so when the tide is high, the lagoon is still filling. The two bodies of water achieve the same level (slack current) well after the tideis on its way back down. The same applies at low tide - the lagoon can't drain as fast as the tide falls, and slack happens well after low tide, when the tide is well underway rising. (Slack at Skookumchuck happens 1 hour 45 minutes, plus 5 minutes for every foot of rise in the previous incoming tide, after high water at Pt. Atkinson . ( If you can think that one through, you will better understand the whole matter). Now to apply this to Georgia Strait and English Bay, you have to consider the fact that we, too, are in a body of water with restricted entrances; Active Pass, Seymour Narrows, and all the rest. Thus our current will lag considerably behind the tide. It will become more predictable in the First or Second Narrows than in English Bay. We cannot expect the simple in and out current that we keep looking for.

Reason 2. One extremely important and not sufficiently recognized input into English Bay currents, is the Fraser River. During the freshet (spring runoff) the water rushes in past the Point Grey Bellbuoy at an amazing pace. You are partially "as if in the river". Sailors see "tide lines" and think it must be the beginning of the incoming tidet. While tide lines can often be treated as such to good sailing advantage, that's not what they are. Fraser (fresh) water is lighter than salt water. What we normally call a tide line is usually salt water sliding under Fraser River water. It can happen at just about any tide. In English Bay, the incoming tide goes partially into the Narrows, but some of it circles around and heads back toward the west ­Ñpast Kitsilano, to meet more-direct-from-the-Fraser-and-less-salty water, which slides over it. Therefore more "tide lines" are seen later in the incoming tide, and they are not consistent.

Reason 3. It is also easy to underestimate the importance of wind over water in causing current. The Fraser fresh water layer is what is called slippery-water, and can be blown over the heavier layers beneath. Illustration: Have you ever wondered why you have to go down the coast well past San Francisco before it warms up much? It is explained by the wind pattern centered in northern California, which blows the warmer top water off, exposing the lower/colder layers of sea water, and bringing colder air onto the land.

Reason 4. Coriolis Force. Currents away from the equator will seem to curve. Water in motion, by sheer weight, would like to go in a straight line. But a straight line on the rotating earth seems more like a curved line. How come? Imagine yourself on one side of a merry-go-round, throwing a ball to a person on the opposite side. Because the merry-go-round is spinning, the ball will appear not to move straight, but to curve. So imagine yourself at the North Pole of a spinning planet, throwing snowballs at Hawaii. Before they melt they will take a similar apparently curved path. The coriolis effect has little effect on our sailing, but is mentioned in case I write a similar article on wind, which would make more reference to the coriolis effect. (Note the common term "coriolis force" is a mistake. It is not a force but the simple result of the fact that a body in motion tends to continue that motion. (Is that Newton??) In 1958 the world's biggest non-nuclear explosion was a response to tidal current, when Ripple Rock was blasted in Seymour Narrows. The rock had claimed 120 ships and 114 lives. After futile efforts to drill down from a barge (1) a long tunnel was drilled under the narrows (2), and 1375 tons of explosives were moved in. Boom (3)!

Next month's challenge question: You want to sail west across the ocean. You may choose from three conditions:
a) water moving 10 kn toward the west (current),
b) air moving 10 kn toward the west (wind), or
c) both.
Which do you choose for the best speed? Your answer requires and explanation.

NEW YEAR'S DAY RACE

Brian Ferris reports: The weather was sunny and just before the race started there was not much wind and a short course was decided on. However 5 minutes after the race started the wind increased. Some of the boats stayed of for the Polar Bear Swim but as my crew was threatening a mutiny I was forced to head to port.

Performance class (2 boats) 1. Whippet 2. Broos Cruising Class, 4 boats, 1. Mumbles II, 2. Lodestar 3. Makai 4. The Saltaire

ROBBIE BURNS DINNER/CRUISE

There was the usual good turnout for the Robbie Burns Dinner at Bowen Island. There were not only about 20 members from Tiddly Cove Yacht Club, but about an equal number from Eagle Harbour Yacht Club. The affair was carried out in grand style with the haggis, piper and all. The weather was a bit choppy on the way over, and very smooth on the return trips (it's probably good for that old motor to get a throrough warm-up in the middle of winter!)

COMING EVENTS

AND WHAT ABOUT SAILING IN THE REST OF THE WORLD?

Well for one thing, there are THREE attempts underway to beat Bruno Peyron's current Round-the-world record of 64 days, 8hr, 37 min., for the Jules Verne Trophy. The current challengers all started at different times. They are:

1. Steve Fossett in Cheyenne, now in day 22, and sailing madly among the icebergs of the Southern Ocean, having just passed the Kerguelen Islands. They just had their best day, averaging 23.87 knots.

2. Gemini - a trimaran, now off Canary Islands, after 3 days out. They have been a little slow, jybing downwind in less than the forcast wind.

3. Orange 2, sailed by the current record holder, Bruno Peyron, is a huge catamaran, close behind Gemini timewise. Gemini is opting for straight line, and Orange 2 is sailing at 15 knots close to the coast of Africa at 25¡ north .(Later update: Orange in trouble, vibration-delaminataion problem - repair at sea doubtful - will probably withdraw)

And then there's the impending America's Cup. Valencia, Spain payed mega-millions to have the event staged there. At first there was talk that the two big billionaire supported efforts, Alenghi and Oracle would so dominate the event that other would be discouraged from challenging. After all they had grabbed up 250 of the best sailors in the world, and had their campaigns well underway before the 2007 site was chosen.

This doesn't seem to be the case. The people of New Zealand were crazy-involved with the last one, but that's only little New Zealand. Now it's in Europe!, where there is far more money, sailors, and TV potential. The advertising value of having a boat involved is apparently enough to finance it, considering the amount of boating interest and the fact that Spain's time zone makes live-time viewing at a reasonable hour throughout much of the world. An interesting comment by one of the planners, "San Diego was a write-off.

And the Mirabella V is worthy of mention too. Just launched, the biggest single-masted ship ever. At 247 foot, and 765 Tonnes, it is BIG. The 290 foot mast cannot get under the Golden Gate Bridge, or through the Panama Canal, and a 33 foot draft must be somewhat limiting as well. It required many a new technology, development of new sail cloths etc. and etc. A picture does nothing one can't grasp the scale, so I send a picture of the bow-furler fitting. For more, put the name Mirabella V in your search program.

Also a guy (Van den Heede?) is setting a new record for sailing around the world the "wrong way" He has an 80 foot cutter - and will finish well ahead of previous records. It is his 4th try. More on that next time.

NOBODY OVER THERE IS INTERESTED IN SAILING

The new design has a variety of races preceding the real thing. More on this later. And we've had a winter of selection regattas for the Olympics in Athens, 2004. An interesting difference in philosophy, the European approach is to pick the most consistent winners over a series of regattas (anybody can have a bad regatta at some time), and the American model is to gamble everything on one big regatta (it is much more like the actual Olympics, seeing who can stand up when the pressure is greatest) Which would you choose??

VARC REPORT (Vancouver Area Racing Council)

VARC is making a few changes this year. Spring and Fall Series will be replaced by the Regatta and Distance series. There will not be divisions 3 & 4 (light and heavy) so that the divisions will be larger. Slower boats will be racing PHRF in Divisions 3, 4, 5, or Open, while faster boats will be racing ORC Club handicap system, or Open Class. Also, the individual clubs will take a greater part in putting on the regattas they sponsor, including any social activities. See varc.bc.ca.