Expedition Expedition Navigation Software

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2/11/2021 4:34 pm  #1


Expedition system for a small boat

Gents-
I'm kind of new, and I'm looking to set up a system for a small boat.  

ClassGlobe580.com – Build your own MINI and race around the world, or the bay!

I know I'll be using a small laptop (probably a Panasonic Toughbook) coupled with an Iridium GO.  We aren't allowed wind or knot/log instruments, but I can see setting up those systems for testing and such and pulling them off of the boat for the races.  I'm thinking an ultrasonic BSP indicator.  We're pretty limited in that we can use solar panels only (no wind, water, diesel) for recharging, and those have to power nav lights, electric outboard, nav/comms, AIS, etc.

If anyone's set up a system like this, I'd like to hear about your experience, but all comments welcome.

Thanks,
Jack

 

2/12/2021 7:27 am  #2


Re: Expedition system for a small boat

Not really sure I understand why no wind or knot/log... without the wind instruments matching up the wind you are seeing with what you are expecting is going to a very manual process when you are very tired. There is no time I appreciate Exp doing maths and presenting images more then when I haven't slept and we're trying to make a tactical decision. Or trying to figure out if the grib wrong, early, or late... having strip chart graph of the wind at that time is a godsend.

 

2/12/2021 5:20 pm  #3


Re: Expedition system for a small boat

I think they're trying to emphasize old school sailing and looking around rather than on board data analysis.  There's some value in seeing what's happening rather than relying on instruments.  Like learning long division before using a calculator.

GPS info is okay.

The real value to me, I think, is that no one has a set of polars for these boats, so to get some put together before the race will really help in routing.

     Thread Starter
 

2/23/2021 7:19 am  #4


Re: Expedition system for a small boat

Jr
You might find a set of polars here for a 'Mini-Transat'
https://spp.elpatron.me/polarfiles
You will have to modify the format for Exp but it will give you a starting point
Like any polar they will only be as good as the 'real' data you tweak them with.
Good luck with your project
Ernie

 

2/23/2021 7:26 am  #5


Re: Expedition system for a small boat

Thanks Ernie!

That will be a big help.

     Thread Starter
 

2/23/2021 7:28 am  #6


Re: Expedition system for a small boat

and another individual boat for comparison:
https://jieter.github.io/orc-data/site/#GRE/FRA222

Cheers,
E

 

2/24/2021 6:33 am  #7


Re: Expedition system for a small boat

jrjohnson wrote:

Thanks Ernie!

That will be a big help.

Not sure polars for a Mini 6.50 will translate to a 5.80.  I just went through my catalog of old Pogo 2 files.  No polars, just cross-over charts.  They have some numbers, but the numbers are way off.  7.8 knots in 20 knots of breeze at 90 TWA.  No way!  Speeds are much higher.  

Best bet is likely going to be to empirically generate polars yourself, or grab a file from somebody who has empirically generated polars for a 5.80.

Separate issue.  I'm 5'10".  After sailing my Pogo 2 to Bermuda, my knees were killing me!!!!  Hopefully you're 4' tall.

 

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