Creating a chart of the gulfstream

[phiggins]

Today I started planning our routes to take my boat back to Fort Myers from Isla Mujeres Mexico. My friend said its easy its a straight shot 408nm and we have the gulfstream with us. You can see in the first attachment Route 1 and my proposed longer Route2 through the Boca Channel which is 439nm

I got to wonder if his statement was true about the gulfstream so I opened up Passage Weather and looked a their map of the gulfstream. Trouble is its not easy to judge where our routes intercept it. See second attachment.

So I decided to make a chart of the Passage weather map using GE2KAP which is actually very easy. First right click om the map and save it as a png called Gulfstream. Use any image editor to crop it to its borders at 30N. Third create a calibration file called Gulfstream.txt that contains: North=30.000 South=18N.000 West=-100.000 East=-76.000 and store it in same directory as the png. Then create a chart using GE2KAP with the png as the overlay but don't overlay on GE.

You can see the result in the last attachment. Going via route 1 we would be going nearly directly into the gulfstream for 80nm as it heads south from the Gulf of Mexico. The second route rides with the gulfstream.

The other reason route2 is better is usually the winds are from the east or south and route1 would have it right in our face if from the east. Could make charts of Passage weathers wind and wave maps to.

[UNCIVILIZED]

So what is it that you're asking?

[phiggins]

I am not asking I am sharing how to create a chart of the gulfstream.

[boatman61]

Its called 'Good Pilotage'
The use of all available information to make passages as trouble free as possible by working with nature instead of against it like so many seem too today..
Have a grand trip..

[UNCIVILIZED]

My apoligies for the misunderstanding. And yes, I too, am of the opinion that one should use all available resources in order to make passages easier. And to move with the winds & seas aiding you, whenever possible.


I hope that your sea surface temp gauge is functioning well, & that you have a grand trip, filled with lots of good memories.
Plus... if you catch a fish that's just a little too big for ship's company to consume...

[svHyLyte]

Ah... You might want to shape your course to take advantage of the Stream. Get into the south bound eddy on the east side and ride it south on the west side to somewhat north of the west end of Cuba, curve westerly to get into the southern back flow between Cuba and Mexico and then westerly again to enter the northbound side of the Stream and approach Isla from the southeast. In the manner you take advantage of the Stream and have favorable winds almost the entire trip as an alternative to fighting against the Stream with wind and Stream opposed (your Route 2). Sometimes the direct route isn't the most favorable or comfortable or fastest.

FWIW

[phiggins]

Thanks but we are going from Ilsa to Florida but will keep that in mind when we return in the fall.

[malyea]

Great product and excellent instructions. I'll be doing GS surveys and NOAA buoy deployments between St Augustine east bound across the GS then south and southeast to the eastern boundaries of the Bahamas. Your effort is much appreciated! Thanks.

www.facebook.com/BlueOceanSails

[deblen]

This link may be helpful. It is supposed to be a live presentation of wind,current,water & air temps,etc.
Click on the Earth button , if the site opens in wind mode, to view current,etc.

earth :: a global map of wind, weather, and ocean conditions

[phiggins]

Very interesting to see the currents around the world. I watched a documentary on Antarctica the other day and they mentioned about that stream that circles Antarctica.

Thanks will keep this link.

[UNCIVILIZED]

It's far from current, or fully comprehensive list (but then, what is). However, you can find LOADS of weather links & tools, here BowmansUnion SailHead Weather Extreme Sailing
Plus, of course, there's about 1,000,001 others out there

[Jeanneau 45.2]

Originally Posted by UNCIVILIZED

It's far from current, or fully comprehensive list (but then, what is). However, you can find LOADS of weather links & tools, here BowmansUnion SailHead Weather Extreme Sailing
Plus, of course, there's about 1,000,001 others out there

Can't help myself ... but noticed the pun where you say "far from current" talking about gulf stream current data. At least I found it funny ....

[phiggins]

I hope that your sea surface temp gauge

Unfortunately we don't have a temperature gauge on the thru hull. So I was trying to think how we could take the sea temperature. Suddenly I remembered we have one on those laser temperature guns that we use to check the engine temperature (the sender is broken on engine). So tried the gun on the sea and it works.

[sophiedaisey]

Enjoyed your description and sharing of the map making and have a great trip


Sent from my iPad using Cruisers Sailing Forum M. Gray Pacific Seacraft 31

[phiggins]

Just before I leave on a long trip on the boat I download all the latest wind, wind, rain and Gulfstream zip files from PassageWeather so that as the trip progresses I can check what the weather is like. But to be able to select the correct file to look at I have first determine the current UTC time, then get the UTC time of first file, calculate the time difference and then load the weather file that is closest to the difference.

So I have wrote a program that does the above and also optionally creates the calibration files if you want to create a chart from the Passage Weather file to display on my navigation program.

Below are some snapshots of the steps:

1. Select which png file then press LOAD PNG.
2. Program loads the png so you can get enter the UTC date/time
3. Program loads the best chart for your current time. This may be all that is needed but if you want to create a chart...
4. Press Calibrate and it will ask you to enter the crop coordinates then crop the png file and save it.
5. It will create the calibrated png...
6. Which you can create a chart with GE2KAP and display on OpenCPN.... ohoh