How to Navigate the Strong Currents and Dangerous Waves of Deception Pass

   How do you safely navigate Deception Pass currents?  

 Deception Pass can be safely navigated by timing your transit near slack current, four times daily, when fast-moving tides briefly settle. This narrow pass can produce strong currents, whirlpools, and standing waves, especially when the wind opposes the tide. Most boaters wait for calm windows, or simply run through nearby Swinomish channel.

Deception Pass is located in Deception Pass State Park in Washington. It is notorious for strong tidal currents and swirling eddies. It is the starting point for many heading to the San Juan Islands, and the bane of skippers who ignore common knowledge.

The pass can be treacherous for boaters and kayakers. But in reality, other than being a tiny bit narrow, it is not much different than Cattle Pass, Thatcher Pass, or Peavine Pass. Here are some tips for navigating safely.

The safest way to navigate Deception Pass is to go through at slack current.

Looking inbound at what is actually two separate bridges.

You can see the narrow slot of Canoe Pass on the left side, and Deception Pass on the right side.

First, let's understand that in the San Juans, Puget Sound, Gulf Islands, pretty much everywhere, there are nasty places where you can get into trouble if you are prone to doing stupid things.  Driving into a storm or wild surf with breaking waves is a mistake for most of us regardless of our boat or skill level.

That being said, the rising/falling tides cause currents.  Large tide ranges usually mean faster currents. Narrow passes or jutting headlands tend to intensify things. Add to that, strong winds and storms and you get places to avoid on your vacation cruise.  

Deception Pass is very narrow, but only narrow for a short section directly under the bridge.  Consequently, the high current speed and accompanying swirlies and waves are confined to the area near the bridge. 

 As you approach the bridge, you notice your speed or lack of it, rapidly changing, making you acutely aware of your boat's top speed.  Most sailboats don't have the top speed needed to overcome normal pass conditions on a calm summer day. The water may be mostly flat, with minimal whirlpools, no waves, and yet the boat stalls out under the bridge, with the skipper wishing 

San Juan & Gulf Islands Current Atlas - Strait of Georgia - Haro - Rosario - Juan De Fuca

  What is a San Juan Islands current atlas or map?  

 Re-posted  because currents in the San Juan's are part of every day and every cruise.

If you are serious about working the San Juan currents to your advantage, you will want to purchase this current atlas, which is produced by the Canadian Hydrographic Service.

  The Atlas is available at West Marine as well as many retailers for about $30

To use the Atlas without doing any math, you will also want to purchase an annual page index such as Washburne's Tables for about $7 (you will need a new one each year)

Some geniuses have posted their own yearly index tables online that you may copy for free.

(try this one  http://code.borsboom.io/current-atlas-tables/) We simply copy and print the online index table for the dates we are on the boat and then use the same dog-eared current atlas.

The Current Atlas consists of about 80 pages, each page is identical, 
except for the direction and size of the arrows.  

 Below is a scan of part of one page from the current atlas.

This is confusing so I had to read the next section more than once.

  Each page represents the current direction and velocity forecast for one hour of that day. All days and all hours are forecast, some conditions repeat repeat repeat, that's why there are 80 pages and not 8,760, and why you need a page index each year to locate the correct page.  You will only need one Current Atlas (used or new) but you will need a page index for the date of your cruise.  An old index table such as the "2009" pictured above is of no use unless your yacht is a time machine.

The page below, was the forecast for July 13, 2011 at 6:00 pm.  If you wanted to see the forecast for 5pm, 7pm, or another day, you would look at a different page. (this is similar to tide tables, except with drawings)

 The biggest arrows represent current velocity over 2.5 mph, the smallest, under .25 mph. 
The arrows point the direction of flow.

Notice the whirlpool (eddy) south of Victoria and off San Juan Island. Notice the current flowing south on east side of Orcas and north on west side of Whidbey.

When cruising, having this information handy can save you time and fuel and make the difference whether you get to your planned destination. For instance a boat heading north up Haro Strait near San Juan Island will get a big boost, however by checking the next several hours one would see that the free ride is going to end soon and the train will come roaring back.  As a rule of thumb the currents flow north on a flood tide and south on ebb tides but as you can see, rules have exceptions.  This forecast is just before the flood tide reverses and becomes ebb, an apt description would be "confused" The confusion will soon end, get your ticket to ride, its free.

This is what the currents looked like on July 13th at 7:49 am, also July 14th at 8:39 am and July15th at  9:26 am.  As you can see, your vessel will get a free ride south just about everywhere, but each day at a slightly different time. When planning your passages and your cruise it would be very helpful to consult the Current Atlas first, a simple free ride one week will be the wrong direction the next week. You may want to choose a different departure date.

While we are on the subject of currents, 

Picture in your mind these big arrows meeting opposing winds and you should then visualize big, steep (dangerous) waves slamming your boat.  Then after a few hours the current changes, and all is well in Camelot once again.
 this post should be read if big waves bother you  >>>wind-versus-current-and-predicting waves
Lately, I have made it part of my cruising to use as little fuel as possible, one cruise we covered about 120 miles over 8 days and used 6 gallons of gas, and most of the fuel was used battling an opposing current between Jones Island and James Island. Unfortunately, my schedule dictated the time.

How to Predict Current Direction in Swinomish Channel

    What direction does Swinomish channel flow?  

Easy answer, it flows both directions.  Sooner or later, regulars to the San Juans learn to love or hate Swinomish Channel.

  Many skippers form an opinion on their very first transit through this popular eleven mile alternative to Deception Pass. Sailors and under powered puttsters fighting the current, hate it, but turn them around and  suddenly their tune changes as the current whisks them along at 

four miles per hour.

         One day we pulled in to the city float at La Conner and I grumbled to a local boater about how we had been battling the current for hours on our way from James Island.  I remember his comment, he said, "The current flows one way for twenty three hours and then reverses, and no one knows when."  We all laughed and I figured I should get over it.

         I came across this rule of thumb posted on the Port of Skagit County website for estimating the current direction.  

        The rule of thumb for estimating Swinomish Channel current 
direction at La Conner goes like this:

The current flows   north   from 2.5 - 4 hours before high tide to 2.5 - 4 hours after high tide
The current flows   south   from 2.5 - 4 hours before low tide to 2.5 - 4 hours after low tide
Slack water occurs 2.5 - 4 hours after high or low tide, not at the tide change like in some areas.

          You will still need to consult with high and low tide predictions for La Conner to put these rule of thumbs to use.  Be forewarned, many people consider La Conner tide predictions as hocus pocus because they are often wrong.

      I cannot remember this rule so I am going out on a limb here and offering my own memory trick as follows.   We already know that in the San Juans a rule of thumb is that the current flows north on an incoming tide (flood) and south on the ebb, and we know in the Puget Sound and southern area it is basically the opposite.  So my memory hack is to consider Swinomish Channel as part of and subject to the San Juan rules of thumb.  This means, Swinomish Channel flows NORTH on the flood just like the San Juans, but it is late due to distance.

FYI - did you know that all of Swinomish Channel (at least where land is) is a "No Wake - Slow Zone"

Click below for satellite view of Swinomish Channel North end and Cap Sante

What is "Current Set" - The San Juan's and Puget Sound are full of potential Catastrophes - Ignornace is Bliss

     "Current set" is the direction water is flowing, and not paying attention to the current set can bite the unwary.         

Boaters deal with currents all the time, especially around docks, floats, pilings and buoys.  But we tend to ignore or not be aware of the current set out in the straits and large water bodies.  

  Is it really a close call if you don't know about it?  If a catastrophe almost happens, is it worthy to note?

        When your boat is drifting towards a lee shore, but still has two hours before running onto the rocks is it a big deal?
      Ignorance really is bliss, that's for sure.

         I don't know how many times I have almost sunk, no one does. "We don't know what we don't know."

      I know this though -- one time in medium fog, slowly crossing Rosario Strait heading into Thatcher Pass, we were all staring out the front and not paying attention to our sideways set (side drift) when out of the corner of my eye I caught a movement that turned out to be rocks coming at us fast. (full flood must have been 3+ knots) The current was forcing us sideways straight onto the rocks of tiny Pointer Island. I swung hard over and pushed her to full throttle, our outboard barely pulled us away with one hundred feet and two or three seconds to spare. I shuddered thinking of my family on board and almost quit boating right then and there.

       Another time, just after leaving Sidney Spit to cross Haro Strait, when suddenly out of the dense fog loomed the green aid marking Mandarte Island.  Once again I had not paid enough attention to the current set and was almost swept onto the rocks.

       And again, once we ran out of gas in the "Narrows," and the current quickly whisked us towards an anchored construction barge under the new Tacoma Bridge.
 Quick action switching tanks averted an unpleasant incident with just minutes to spare.

     So, I have admitted to three times that I know of, where my inattention to currents has almost had disastrous results.  How many more are there that I don't know about? I don't know.

     My problem is, I tend to watch where the boat is pointed or where I want to go and not where we are really going. Of course, being disoriented in fog makes it worse.

     Ignorance is bliss, but it's no way to skipper a boat.

You wouldn't cross in front of a ship making 6 knots.

So why pass barely upstream of rocks in a 6-knot current?

Click below for a satellite view of Saddlebag Island State Park