Cruising and Navigation Association of New Zealand

Author Archive

Lightning on Tamaki River

The following photo is, I think, from that Friday thundershower, and has been sent in by Steve Sinclair . Orsum.

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SUMMER CRUISE 2015

Our Cruise director Ross Davenport researched the weather and tides and picked Woody Bay for our 2015 Summer Cruise—it was certainly a popular spot on the evening of Saturday 21st February.

It rained over the Auckland isthmus on Saturday afternoon but remained dry at Woody Bay.  Smile  Good planning.

Stephen Plank’s photo record is now available at CANANZ Summer Cruise (55 images and 1 video)

There was a wind from north by northwest, good enough for sailing, and it did bring a gentle roll into parts of the bay.

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The first CANANZ yacht to arrive was MOKOIA (Our Patron Jim and Karin Lott’s “home “boat), followed by the Plank family on CLOSE ENCOUNTERS, Treasurer Basil and President Bob on PINK CADILLAC, The Davenports on SAN FRAN, and then  Liz and Chris Fotherby on SOUTHERN VENTURE.

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Around the time of low tide  (4:06pm, 0.2m) we all made way to the beach which then had ample room for our gumboot throwing contest.

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The winner of the MAGGIE TROPHY this time was Stephen Plank, just beating a wonderful throw given earlier by his son Cullum.

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The new moon on Thursday 19 February was very close to this month’s perigee (shown on  graph below)  and thus we had a king tide on the 21st.   It was fun watching the tide come in, requiring us to put our BBQs further up the beach. Timing was just right and by the time we were forced back to our boats, there was only around half-an-hour of light left.

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Graph of Sea level from Whitianga (nearest tide station with such a record) from (go to the site for explanation of the codes)

http://www.niwa.co.nz/our-science/coasts/tools-and-resources/sea-levels/whitianga-wharf

In Hauraki gulf the high tide at 10:29pm sat 21st was 3.6m ,

and at 10:56am on Sunday 22nd it was 3.7m, about as high as it gets unless we add a storm surge (SS)

 

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Basil deploying his flopper stopper.

Yes, SAN FRAN and  CLOSE ENCOUNTERS rafted up for a party during the evening. Quantum biology was part of the discussion.

On Sunday morning all 13 of us gathered on MOKOIA for a collective breakfast at 9am. We forgot to record the delicious offerings, including the dozen cup cakes covered in chocolate icing made for us by Olivia. The various boats then made off in different directions to enjoy the light winds and various delights that Sunday offered.

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For the technically minded here is a graph of the wind speed and direction at Bean Rock during the weekend:

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For a video showing the winds in the Hauraki Gulf on Saturday and Sunday  see

http://youtu.be/ckNC-RAadSk

 

or (with music and an ad) at

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Seven sailing tips for easier navigation

Seven Sailing Tips to Make Navigation Easier

by John Jamieson Professional Sailing and Boating Writer, USCG Licensed Captain (sail and power), Published Author @ www.skippertips.com

posted by Bob McDavitt  

                            Put these seven golden rules of navigation safety into play aboard your small sailboat today.

Put these seven golden rules of navigation safety into play aboard your small sailboat today.

If you are anything like me, it’s rare that you look forward to another mathematical calculation “rule of thumb”. Here are seven simple rules you can use to enhance your sailing navigation safety–without a whole lot of math!

Why know traditional methods of navigation with all the high-tech push-button navigation gear available today? Top sailing skippers use this knowledge to:

Avoid running aground in familiar or unfamiliar waters.
Read a nautical chart at-a-glance with confidence!
Plot Latitude and Longitude with blazing speed and accuracy.
Gain independence from “electronic-only” navigation.
Learn fast, easy methods to check your Gps or chart plotter.

Follow these seven sailing tips to keep your sailing crew or partner safe and sound wherever you choose to cruise!

1. Double-check Courses.

Parallel rules and protractors tend to slip when underway. Just a slight bit of slippage could throw a course or bearing off by several degrees. Take the extra step and measure your plotted course twice. If both measurements agree, you will know you’re right!

2. Keep Bearing Spreads to 60-90-120.

Shoot two or more bearings with a minimum angle of 60 degrees between the objects. This will reduce errors and gives a more solid fix. If you shoot just two objects, the best spread between objects will always be 90 degrees. With two objects the maximum angle should never exceed 120 degrees. Scan your nautical chart ahead of time; find and highlight objects you can use for bearings. This will make your plotting faster, easier, and more fun.

3. Measure Distance with Care.

Because chart projections have some error after being flattened from a 3-dimensional image, distances can distort. This becomes more critical on charts with smaller scales, such as those used in coastal or offshore navigation. Measure distances on the Latitude scale adjacent to your current position for more accuracy.

For example, let’s say you are navigating on an offshore chart with a scale of 1:250,000 (see today’s exclusive sailing video for more on chart scales). If you are located in the center of the chart, measure distances from the central part of the latitude scale. If located near the top of the chart, use the latitude scale near the top to measure distances. If located near the lower part of the chart, use the latitude scale near the lower part of the chart to measure distances. This gives you more accurate distance measurements for planning, provisioning, determining arrival times, and for conservation of water and fuel.

4. Shoot Bearings Ahead or Astern First.

Take visual bearings on objects near the bow or stern first. Bearings to these objects change slowest as you move through the water. Take visual bearings to objects near the beam last. Bearings to these objects change fastest. Mark the time of the position when you have taken the final beam bearing. Enter the time of the fix into the navigation log along with your bearings. This allows you to reconstruct your path over the earth’s surface and provides a historical and legal record of your vessel’s journey.

Use a preceision plotting or drafting compass for fast, accurate sailing navigation.<br><font size="1"> (<i>courtesy of <A href="http://www.staedtler.ca/compasses_ca"/target="new"><font size="1">Staedtler.com</i></font size></A><font size="1"> )</font size><p>

Use a preceision plotting or drafting compass for fast, accurate sailing navigation.
(courtesy of Staedtler.com )

5. Become Plotting Compass Savvy.

Learn to become super proficient with the plotting compass (also called a “drafting compass”). This tool has a needle point in one leg and a small sliver of pencil lead in the other. Few navigation tools are more versatile. Choose a compass about 7″ long overall for comfort and fast, accurate plotting. Note in the illustration the pencil lead (circled in red) inserted into one leg.

Use the plotting compass to plot Latitude and Longitude one-handed, swing an arc from a radar range, or project a series of Dead Reckoning positions ahead of your last position–with a simple sweep of the pencil-lead across the course line. Some navigators might prefer dividers–a navigation tool that has a needle point in the end of each leg. But dividers require a separate pencil for plotting. The plotting compass does twice the work in half the time!

6. Know Your Soundings.

Before you start to use any nautical chart, find out what the soundings mean. Look under the title of the chart (title block area) and on the top or bottom margins. Your chart will say Soundings in Feet, Soundings in Meters, Soundings in Feet and Meters, or Soundings in Fathoms. These are the most common soundings used on nautical charts.

For example, let’s say you see a sounding of 2 on your chart. Does this mean 2 feet, 2 fathoms (12 feet), or 2 meters (6 ½ feet)? Never assume one chart’s soundings are the same as another. Always check the title block and chart margins first before you start to navigate. Pass on this vital information to your sailing crew.

7. Allow for Leeway Error.

Sailing vessels slip sideways (called “leeway”) when beating or reaching. There are fancy calculations to determine leeway, but always work your way upwind of your intended destination to account for unexpected wind shifts or navigation errors. Some navigators like to set their course two to three miles upwind or up-current on purpose. This gives them a good margin of safety and allows them to fall off to a reach or run to the final destination. (See “Related Articles” at the bottom of this newsletter for more on sailing navigation).

Follow these seven easy “rules of thumb” to enhance your sailing navigation safety. Keep your small sailboat and sailing crew safe and sound on the waters of the world–wherever you choose to go sailing!