{"id":1684,"date":"2017-08-15T12:27:45","date_gmt":"2017-08-15T19:27:45","guid":{"rendered":"http:\/\/tradewindssailing.com\/wordpress\/?p=1684"},"modified":"2017-08-15T12:27:45","modified_gmt":"2017-08-15T19:27:45","slug":"tides-and-currents-where-do-i-find-the-correct-information","status":"publish","type":"post","link":"https:\/\/www.tradewindssailing.com\/wordpress\/general\/tides-and-currents-where-do-i-find-the-correct-information\/","title":{"rendered":"Tides and Currents – Where do I Find the Correct Information?"},"content":{"rendered":"

As I write this, I am preparing to instruct a July 27 Advanced Coastal Cruising class. \u00a0Part of the class preparation required of each student involves determining the best time to transit the Golden Gate the morning of July 28. \u00a0One primary factor to keep in mind is the currents. \u00a0To the casual observer, the logical time to leave the bay would be during an EBB so that you can “ride the current out.” \u00a0This is actually the worst time to go. \u00a0The EBB will meet the ocean swell and the wind, both coming in, creating some rather interesting, and sometimes dangerous, conditions the 8 miles from the bridge to the outside edge of the San Francisco Bar. \u00a0I generally time my exit for the slack before the flood in order to avoid the EBB, and have as little Flood as possible.<\/p>\n

However, the best time to exit the Golden Gate isn’t the point of this tip, were to find information about tides and especially currents is. \u00a0I use four different sources (one book and three internet sites) to get expected tide and current data. \u00a0Knowing that, recognize that all four sources are “estimates of expected” tides and currents. \u00a0Basically, that means all four are different, with times varying by nearly 2 hours on the first slack of the day, to a 1.7 knot difference in the 0820(ish) EBB.<\/p>\n

With that much difference, who do you trust? \u00a0Easy, whichever one you happen to have available. \u00a0The important thing is to use something. \u00a0Keep in mind, every source is an estimate. \u00a0As long as you recognize that you will be OK with whichever source you pick. \u00a0More critical than which source you use, is … are you actually remembering what you see? \u00a0Did you look at it and just jot down the slacks and the extremes because that is what you were trained to do? \u00a0Or, are you really making a mental picture of what will be happening during your sail?<\/p>\n

As an example, \u00a0current information for each of the four sources is shown below (along with links as appropriate … bookmark them and use them.)<\/p>\n

Currents 0.2 miles SE of Point Diablo (The Golden Gate)<\/strong><\/p>\n

2017 San Francisco Bay & Delta Tide Book<\/strong>
\n0148 S \u00a0 \u00a0 \u00a0 0218 2.6 F \u00a0 \u00a0 \u00a00512 \u00a0 \u00a0 \u00a00818 1.9 E \u00a0 \u00a0 1130 S \u00a0 \u00a0 \u00a01442 3.2 F \u00a0 \u00a0 \u00a01800 S \u00a0 \u00a0 \u00a02100 1.5 E<\/h6>\n
University of Nevada, Reno Tides and Currents<\/strong>
\nhttp:\/\/wolfweb.unr.edu\/homepage\/edc\/tides\/2017\/sfbe_fr17.html<\/a>
\n0001 S \u00a0 \u00a0 \u00a00222 2.0F \u00a0 \u00a0 \u00a00448 S \u00a0 \u00a0 \u00a00813 3.2E \u00a0 \u00a0 \u00a01155 S \u00a0 \u00a0 1444 2.7F \u00a0 \u00a0 \u00a01739S \u00a0 \u00a0 \u00a02103 2.8E<\/h6>\n
University of South Carolina<\/strong>
\nhttp:\/\/tbone.biol.sc.edu\/tide\/tideshow.cgi?site=San+Francisco+Bay+Entrance+(Golden+Gate),+California+Current<\/a>
\n0237 2.65 F \u00a0 \u00a0 0543 S \u00a0 \u00a0 0825 3.62 E \u00a0 \u00a0 1211 S \u00a0 \u00a0 1510 3.19 F \u00a0 \u00a0 1824 S \u00a0 \u00a0 2102 3.14 E<\/h6>\n
NOAA (see images below)<\/strong>
\nhttps:\/\/tidesandcurrents.noaa.gov\/noaacurrents\/Regions<\/a>
\n0131 1.62 F \u00a0 \u00a0 0401 S \u00a0 \u00a0 0820 3.18 E \u00a0 \u00a0 1151 S \u00a0 1349 2.12 F \u00a0 \u00a0 1655 S \u00a0 \u00a0 2108 2.83 E<\/h6>\n

If I want to time my arrival at The Golden Gate for slack before flood, I should be at the bridge between 1130 and 1200. \u00a0I can expect a flood of varying intensity up to 3 knots for the next 6 or so hours. \u00a0Transiting the Golden Gate and crossing the San Francisco Bar covers approximately 8 miles. \u00a0With a speed through the water of 5.5 knots, it will take about 1:30. \u00a0 However, because of the flood I can expect to add 15 to 30 minutes to my transit time. \u00a0 If I arrive at the bridge at 1130, I should be through the bar by 1330 and able to make a turn south for Half Moon Bay 20 miles away. \u00a0At 5.5 knots of boat speed my arrival in Half Moon Bay should be approximately 1700. \u00a0A quick check of the NOAA tide prediction site indicates a 5+ foot high tide an hour before my arrival. \u00a0Net result, I should have plenty of daylight left and lots water under my keel when I pull into Pillar Point Harbor.<\/p>\n

\"\"<\/a>As far as my personal preferences regarding which source to use. \u00a0I ALWAYS carry a tide book in my PFD and use it if I don’t have internet access. \u00a0If I have internet access, I use the NOAA site because of the options and variety of reporting locations (of the 332 reporting locations found within California waters, there are 39 reporting locations covering every aspect of the approaches to and through The Golden Gate.) \u00a0Predictions are given in both text and line graph formats and can be downloaded in text, excel, or web formats for easy saving and\/or printing. \u00a0And, it’s first person data instead of being interpreted by someone else.<\/p>\n

\"\"<\/a><\/p>\n

In closing, find and use a tide and current reporting source that you trust. \u00a0Understand what the information means, and know what is happening at all times during any sail. \u00a0I feel so strongly about it that if you are in one of my Bareboat or Advanced Coastal classes, at some point I am going to ask what is happening with the tides and currents. \u00a0If your answer is “I wrote it down in the log book,” I will be sad.<\/p>\n","protected":false},"excerpt":{"rendered":"

As I write this, I am preparing to instruct a July 27 Advanced Coastal Cruising class. \u00a0Part of the class preparation required of each student involves determining the best time to transit the Golden Gate the morning of July 28. … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":14,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[4],"tags":[],"class_list":["post-1684","post","type-post","status-publish","format-standard","hentry","category-general"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.tradewindssailing.com\/wordpress\/wp-json\/wp\/v2\/posts\/1684","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.tradewindssailing.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tradewindssailing.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tradewindssailing.com\/wordpress\/wp-json\/wp\/v2\/users\/14"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tradewindssailing.com\/wordpress\/wp-json\/wp\/v2\/comments?post=1684"}],"version-history":[{"count":2,"href":"https:\/\/www.tradewindssailing.com\/wordpress\/wp-json\/wp\/v2\/posts\/1684\/revisions"}],"predecessor-version":[{"id":1689,"href":"https:\/\/www.tradewindssailing.com\/wordpress\/wp-json\/wp\/v2\/posts\/1684\/revisions\/1689"}],"wp:attachment":[{"href":"https:\/\/www.tradewindssailing.com\/wordpress\/wp-json\/wp\/v2\/media?parent=1684"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tradewindssailing.com\/wordpress\/wp-json\/wp\/v2\/categories?post=1684"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tradewindssailing.com\/wordpress\/wp-json\/wp\/v2\/tags?post=1684"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}