Polars

[rbrtmccorkle]

Hi all

Am now about 1 1/2 months away from leaving Portland, OR and working my way towards Panama.  In prepping for this cruise and the passages associated, I've started looking at Wx Routing services.  Seems that in order to avoid getting "Garbage in/Garbage out "  kinds of results, one needs to provide the various services the Polars for their vessel.

     1.  Anyone know where I can find the Polars for a 1998 Bav Ocean 42?
     2.  Any of you have a preferred Service?

Thanks in advance - Blue Skies and Fair Winds

Bob - SV Chaos

[Odysseus]

Look in the app SailGrib most boats are in this app.
Odysseus

[sy_Anniina]

My favourite source for polars is https://jieter.github.io/orc-data/site/ . Unfortunately no Bavaria 42 Ocean found there, but plenty of J&J design 42 cruisers with different sym / asym / no-spin configurations e.g. https://jieter.github.io/orc-data/site/?#ISR/ISR422

BR,

Tommi, s/y Anniina

[Sothis]

You can make your own with iPolar. Just put in basic data:
- Length Overall
- Displacement
- Mainsail area
- Jib area
(units can be set to metric or imperial)
Optional data:
- Length Waterline
- Symmetrical Spinnaker area
- Assymetrical spinnaker aera

https://apps.apple.com/us/app/ipolar/id577106473

Then when you sail you can modify it accordingly if you see big errors.

[Yngmar]

Making your own is likely to give more realistic results. Most of these published ones I looked at are rather optimistic, probably created on stripped out race boats sailed with empty tanks and six people dangling their legs over the windward rail. Certainly a far call from your typical overloaded cruising boat where the autopilot steers most of the time and every once in a while someone squints at the sails and thinks they probably could use a bit of trimming but it's hot and I'd have to put the book away and move. And you're not likely to have the exact same sail wardrobe they have.

[Salty]

Making your own is likely to give more realistic results. Most of these published ones I looked at are rather optimistic, probably created on stripped out race boats sailed with empty tanks and six people dangling their legs over the windward rail. Certainly a far call from your typical overloaded cruising boat where the autopilot steers most of the time and every once in a while someone squints at the sails and thinks they probably could use a bit of trimming but it's hot and I'd have to put the book away and move. And you're not likely to have the exact same sail wardrobe they have.

From what I’ve seen of the figures on the websites mentioned, I totally agree with Yngmar’s comment. I think it is absolutely spot on. On a journey such as the one envisaged by Robert McCorkle from Portland Oregon to Panama, I would have full fresh water and fuel tanks, plus some spare for emergency use, and that would be despite the fact that there would be plenty of accessible ports on the US west coast where those tanks could be replenished. Even south of Mr Trumps fence, there are ports where water and fuel can be obtained, albeit possibly further apart, and maybe of lesser quality. So with that in mind it’s more than likely that the displacement alone would be substantially greater than the sort of figures seen in the examples shown on those websites.

[Mirror45184]

Published polars are a good start. then monitor and modify as you gather information.
Cheers