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Getting past Cape Mendocino: A coastwise passage south from Seattle

Oct 2, 2009

Leaving the complacency of a dock and going voyaging in the big, wide world beyond starts with the first step. In our case that was a 750-nm run from Seattle to San Francisco aboard our Tayana 37 sloop Anna. What follows, is a summary of Anna's big leap out of the Pacific Northwest: the left turn at Cape Flattery, Wash., around Cape Mendocino, Calif., and on past the "lost coast" and Point Reyes, Calif., the last major tumultuous headland before the Golden Gate.

The passage included a couple of three-day, two-night passages &mdash in actuality, open-ocean shakedowns &mdash as well as a couple of one- to two-day near offshore legs between Cape Mendocino, Pt. Reyes and the Golden Gate Bridge. To round things out, along the way, we opted for one bar crossing at Humboldt Bay, the dicey entrance to the safe haven at Eureka, Calif., and gateway to infamous Cape Mendocino and all points south.

On a 750-nm passage, from the Pacific Northwest to the San Francisco Bay area, a variety of routing options are available to a voyaging vessel, including: short harbor-to-harbor jogs; longer, one- to three-day offshore passages; or simply a direct, non-stop offshore passage. There are compelling reasons for completing this journey, by using any single option or combination of options. Everyone who attempts this rite of passage regardless of how they accomplish it will have a story to tell: "a brutal offshore ride across building cross seas, obscured in heavy fog;" or perhaps "ghosting along glassy waters, the Cape Mendocino light clearly visible just a couple of nautical miles off."

Cape Mendocino is well known &mdash infamous, in fact &mdash for its complex weather patterns and equally complex wave sets that finish their long ride across the fetch of the North Pacific, only to reflect back off its massive, projecting headland. This is an area of volatility. Its sphere of influence may extend for hundreds of miles offshore. Serious weather systems develop here when a deep inland low-pressure zone to the east of Cape Mendocino collides with a strong, relatively stationary North Pacific high. In the mild summer month of July, the pilot charts for the North Pacific Ocean indicate that there is only one area, in the entire North Pacific that has a greater than 10 percent chance of gale-force conditions. On the chart, it is defined by a conspicuous, red oval contour line &mdash extending 50 to 250 nm offshore &mdash off Cape Mendocino.



Offshore and inshore routing strategies

It is probably fair to say that once a boat exits the west entrance to the Strait of Juan de Fuca &mdash the 70-nm international water boundary, that separates the U.S. and Canada &mdash and heads out into the North Pacific, there is a pretty good chance that it will encounter a variety of weather and sea conditions along the way to Cape Mendocino.

Weather-forecasting models, while remarkably advanced, remain by nature a work in progress. Unequivocally, it comes down to a question of good timing and luck &mdash though perhaps luck is less important as our short-term forecast models gain higher levels of sophistication and achieve higher levels of confidence. On this stretch of ocean and hostile lee shore, only one thing can be taken for granted: there is no one indisputable and correct way to complete this long gauntlet of weather systems and sea conditions. This is a dynamic body of water, set in the midst of a dynamic area of weather, and conditions will change &mdash often enough, much too rapidly. And with this in mind, some skippers will move well offshore &mdash hundreds of nautical miles, in fact &mdash further away from the dangers of a rocky coast and a cape that can wreak serious havoc with any vessel, large or small. Conversely, the other strategy is to run close enough to the coast to reach cover when bad weather is forecast to move in &mdash that is, run for the shelter of a protected harbor if time permits. There are advantages and disadvantages to both approaches.

An offshore route puts a large distance between boat and coastline and it affords more time to ride out heavy weather, without yet another thing to worry about: a reef, a treacherous bar crossing, scattered commercial fishing fleets; obstacles that we are happy to eliminate from the equation. On the other hand, an inshore passage can make a run for cover a possibility, but this assumes the safe crossing of a potentially treacherous entrance bar. Along the 600 nm of hostile coastline, between Cape Flattery and San Francisco there are very few safe havens that don't require crossing an entrance bar, a seriously dangerous maneuver when conditions deteriorate. Timing the entrance when crossing a bar is everything. The entrance bar to Humboldt Bay and the safe haven of Eureka is no exception. Nevertheless, Humboldt Bay is alluring. It is home to a strategically located and cruiser-friendly national weather service station. The National Oceanic and Atmospheric Administration's National Weather Service (NOAA NWS) is where weather forecasts originate, for the waters that surround Cape Mendocino and that extend out, hundreds of nautical miles to the north, south and west.



Wind and wave angle

Anna crossed the Humboldt Bay bar and entered Eureka's protected waters after sailing a couple of large, offshore triangles (from Cape Flattery to Newport, Ore., and then from Newport to Eureka). We wanted to understand, firsthand, how the conditions of weather and sea state affected the ride at various offshore distances ranging from five to 150 nm out on the southbound run towards Cape Mendocino. What we found was that moving offshore provided us with a steadier breeze for sailing. Waves (combined ocean swell and wind waves) tended to be somewhat higher, but they were smoother, too, due to their longer periods and easy, rolling, swell components. Generally, we did not find significant differences in sea conditions within the range of 60 to 150 nm offshore on the southbound run. We did notice less vessel traffic as we moved further and further offshore, beyond say, 40 nm from the coastline. But during the fishing season, larger fishing boats with their obstacle course of marker buoys bobbing at the surface, do not disappear completely until you are a lot further out. Moving further out seemed to help make our night watches somewhat less demanding. There are fewer floating obstacles to avoid when you are hundreds of miles out: fewer unlit boats, floats and debris that can be difficult, if not impossible to see after nightfall.

Sailing through a big swell in a steady breeze off the aft quarter is, in our opinion, both enjoyable and preferable to a ride through small, choppy, confused wave sets, reflected off of an extended point or cape. Sometimes, when confused waves are accompanied by big gusts, an exaggerated, nauseating, washing-machine effect can occur, even on the most sea-kindly boats. Anyone with a normal inner ear or sense of balance is soon hanging their head over the side, feeding the fish and asking the question: "are we there yet?"

It is true, that weather buoys along this area of coastline tend to indicate stronger winds and higher waves offshore, but this is not necessarily a bad thing unless the wind and wave angles combine to become uncomfortable or dangerous, or if they force us to modify our intended course for a smoother and safer ride. We consistently find that a good wind and wave angle and a steady breeze are the key contributors to our level of comfort as the weather gets heavier and as the seas grow larger. Moreover, wind and wave angle have a huge influence on our routing decisions. We will always take the tradeoff of adding more nautical miles to a passage if it means an increase in our levels of comfort, safety and enjoyment.

On one of our NE Pacific crossings, from Kaua'I, Hawaii, to Vancouver Island, British Columbia, we closed to within 450 nm due west of Cape Mendocino, on our final approach to Vancouver Island. We passed through a series of intense, low-pressure systems, which were lined up and on the move across the North Pacific. With waves of 25 feet and gale-force winds, it was not unlike conditions that are often reported by sailing vessels closer in, between 50 and 250 nm off Cape Mendocino. The big difference, however, was that we were moving north and east, riding a series of intense low-pressure systems with wind and seas off our aft quarter &mdash a nice ride, really. But getting caught in an intense low while moving southward along the coast off Cape Mendocino is a whole other story &mdash it is uncomfortable (to put it mildly) and potentially dangerous. There is no place to run for cover &mdash the bars will probably all be impassable. That is exactly why many boats choose to stay further out, away from the hazards of a rough, lee shore. Vessels that are within a couple of hours of shore, when making their approach to Cape Mendocino or one of the other havens along this stretch of coast do, however, have the option of making it across the bar if their timing is good and they head in before life gets interesting.



Safe haven before rounding the cape

On a clear day when stable, light to moderate weather conditions prevail, sailing or motoring close to the Cape Mendocino coastline can be a excellent strategy for advancing in either direction &mdash north or south. Local fishermen often hug Cape Mendocino close by as weather permits. We had unstable weather predicted in the 24-hour forecast, as we began to approach the area to the northwest of Cape Mendocino about 80 nm out. Our strategy was to work our way in on a comfortable wind and wave angle while the weather was still good; arriving at the Humboldt Bay entrance bar on a slack tide just as it was beginning to flood. We could then wait comfortably, in the protection of Eureka, for a nice weather window to safely continue southbound, around the cape and on towards Bodega Bay or Point Reyes, or maybe the entrance to the Golden Gate Bridge. Eureka, located just 10 miles to the north of Cape Mendocino is ideally located for southbound vessels because of its proximity to Cape Mendocino. When a 48-hour weather window opens, a boat sitting in Eureka is well positioned to make its move south.

When we where within one hour of the Humboldt Bay entrance bar, the U.S. Coast Guard station informed us that the bar was open to vessel traffic and that crossing conditions were considered to be good. Of course, the trade off of planning a bar crossing is that conditions can change quickly and the Coast Guard will not assist you if they determine that bar conditions are too dangerous to permit vessels to enter or exit. They can, and they will, close the bar and advise you to head out to sea. When conditions are reasonable, however, one can expect an uneventful bar crossing. The Coast Guard does offer assistance with the crossing when the bar is open to vessel traffic. You should contact them within one hour of your estimated time of arrival for a status update on bar conditions. They can meet you at the entrance and guide you in, or advise you on VHF radio on how to proceed. You can also cross the bar unassisted.

Eureka is a good place to stop along the way, breaking up the journey and giving you a chance to stretch your legs, in a cruiser-friendly town with many amenities. After we crossed the bar, we proceeded to the public docks, a few miles away. There was a strong current in the dredged channel and it made handling our full-keel boat tricky when attempting to dock. But there are end ties and linear docks lined up in the right direction and the harbor master is accommodating. We were able to find &mdash by dumb luck &mdash a small dock that was aligned perfectly with wind and current and that made life easy. We just drifted with the flow of the current onto an ideal little end tie located at the entrance to Eureka's old town district. That is where we moored for our first couple of days. Quite by accident, we discovered, while on one of our walks by the docks, that a NOAA weather station was close by (see sidebar).

By the time we left Eureka, we were on a first-name basis with the NOAA people. They were extraordinarily helpful. Our friends at NWS, Eureka, were kind enough to review their computer models with us and give us insights into their analysis. In addition, we were able to obtain local knowledge from some friendly fishermen who dealt with the bar and Cape Mendocino on a daily basis &mdash solid, pragmatic info. As a result, when we finally did leave Eureka, our run over the bar, around the Cape and on into Bodega Bay was, well, rather unremarkable.

All of the computer weather models for the day we chose to make the run south happened to agree &mdash a good sign. When we left, the winds were light, and the tide and current were turning to slack flood. The swells at the bar were low (less than six feet) and there were no noticeable breakers off the south jetty (the north jetty did have breakers, however) and so we favored the south side. The sky was clear, with unlimited visibility. The only glitch was that the winds never developed to more than NNW 5 to 15 knots. Anna is heavy and broad reaches down waves, sweetly, in 15 to 20 knots, or more. The 5- to 15-knot breeze was a bit light. Nevertheless, it was a reasonable trade off and we did not regret it for a second.

It was the end of September and the days were sunny and mild, and the nights were Milky Way clear and cool. The stars lined up for us, on that spectacular day and evening and throughout the night. We ghosted along, just barely offshore, Cape Mendocino in clear sight.

We enjoyed the extraordinarily pristine scenery of the remote "lost coast," a sight missed, unfortunately, when standing well out to sea. The NWS Eureka predictions were accurate and 48 hours later the weather degenerated. The NOAA station at Eureka is a wonderful resource that voyagers do not seem to know about, but ought to &mdash especially before considering a run around Cape Mendocino.



Rich Ian-Frese and his wife Cat sailed an 11,000-mile Pacific Ocean loop aboard their Tayana 37 cutter, Anna.
 

Crossing the bar and rounding the cape

What really occurs when you try to cross an extremely shallow entrance bar on an ebb tide, running at 4 knots and set against a west wind of 30 knots or more, with combined seas of more than 10 feet, is that big breaking waves cascade down across the entrance. This makes crossing an entrance bar nearly impossible and very dangerous &mdash it is simply a very risky business when conditions are bad.

The best way to cross the Humboldt Bay bar and then round Cape Mendocino, for example, is to get your timing right. The decision has to be based on local knowledge, and the NWS Eureka can help you increase your odds of passing through safely. The Coast Guard monitors the bar and they will give you their assessment, which is handy because they are right there, watching it from their tower. They can advise you if conditions are dicey before you find yourself facing a big breaking wave in a small channel.

You need patience to wait for the best weather window, as well as the correct tide and current conditions. Rarely do all these parameters match up. Our departure from Eureka occurred at 0700, the projected best time on that particular day, to cross the bar and then round Cape Mendocino and continue through to Bodega Bay, some 185 nm to the south and east. We wanted to arrive there within 36 hours to avoid being caught up in the next storm system that was forecast to arrive within about 48 hours. It would require an overnight passage of approximately 30 hours. NWS Eureka made projections for all weather zones in between Eureka and Bodega Bay to exhibit moderate winds and waves.

Rich Ian-Frese
 




A visit to NOAA NWS station Eureka



NOAA NWS Eureka is located on Woodley Island, by a public marina and across the bridge from old town Eureka. They are open for normal business hours Monday through Friday, between 8:00 a.m. and 4:00 p.m. local time and can be reached by phone at (707) 443-6484. When we visited the station we had no specific plans to tour the facility, we simply wanted to obtain the latest postings of their 24- 48- 72- and 96-hour wx-forecasts so that we could start to form a strategy. We needed an exit plan for re-crossing the bar and, of course, rounding Cape Mendocino 10 miles to the south. To our surprise, when we arrived at the NWS Eureka doorstep, unannounced, we were invited in for a look-see. We were introduced to their team of meteorologists who were responsible for generating the marine weather forecasts for Cape Mendocino and the surrounding waters. They walked us through the station and its array of computers, which displayed various weather models and associated raw data. Their job was to analyze and interpret and interpolate the data &mdash make sense of it all &mdash and then generate a simple text report, distilled from complex information. Their updated forecasts would then appear a few hours later, posted on the Internet and broadcast on the VHF-radio weather channels. It is fascinating to see this process in action.

We returned over the next couple of days, with a question or two, after we thought a bit about what we saw and after thinking about how we could best use that information to form an exit strategy. The people at the weather station were happy to share their ideas with us and together we were able to concur on a plan. We used their predictions for localized sea state, winds, and bar conditions based on the projections of their multiple wx-models to narrow down a date and time of day for our tentative departure. As the time drew close they asked us to call them (even at 0500 &mdash they would be there) when we were ready to go, just to make sure the computer models still looked good for our estimated time of departure. Because weather reports are posted to the Internet and broadcast over VHF channels, typically six hours or more later than they are generated, the prospect of receiving a real-time report directly from the forecaster is a definite advantage.

When we listened to the 0400 VHF radio broadcast, it warned of potentially dangerous waves in the area that we would be transiting. However, after speaking with the meteorologist who wrote the report, earlier in the morning, we were told that the computer models had since changed &mdash changed enough, for them to remove the warning. The new forecast would not be available to the general public until the next scheduled broadcast, later that morning &mdash well after our intended departure time. But with advance notice that the dangerous wave warning was eliminated from the mix and that all four of the computer weather models concurred (not something that happens often, apparently) we were encouraged to take advantage of the excellent weather window, which had just opened and was projected to last for the next 48 hours.

Rich Ian-Frese
 

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