Hobie Forums
http://www.hobie.com/au/en/forums/

Where can I find Polar Speed Charts?
http://www.hobie.com/au/en/forums/viewtopic.php?f=9&t=10337		 Page 1 of 1
Author:  Inland Sailor [ Tue Aug 12, 2008 10:18 am ]
Post subject:  Where can I find Polar Speed Charts?
The Hobie University PDF in product support at this site shows a polar speed chart of boat speed vs points of sail for a Hobie 20. Does anyone know if similar charts are available somewhere for the full Hobie lineup?
Author:  Banzilla [ Tue Aug 12, 2008 7:13 pm ]
Post subject: 
There is one for the H20 here, download the PDF

http://www.hobieclass.com/default.asp?Page=1686
Author:  MBounds [ Tue Aug 12, 2008 8:17 pm ]
Post subject: 
The very short answer is that they don't exist.

A polar diagram for a small boat, especially one that can surf, is all but useless. There are too many variables to represent on the graph.

Boat speed is a function of:
- wind direction
- wind velocity
- crew weight
- boat weight
- wave state
- wave state orientation
- boat set up

Last but certainly not least:
- crew skill

A polar diagram only takes into consideration the first two.

The H-20 diagram in the Hobie U book is merely a representation - it is not based on actual measurements.

You can create your own polars with a GPS and a program like GPS action replay. This is one from my 17 in about 5-10 kts of wind:
Image

You can see that most of the sailing was windward / leeward (it was the last two races in a regatta last fall). The reaching portion of the graph isn't fleshed out.

Interesting that it shows I could sail faster and deeper downwind on port tack.
Author:  Inland Sailor [ Wed Aug 13, 2008 6:38 am ]
Post subject: 
MBounds: It looks like you've been at this awhile. Thanks for the reply. I understand there are many variables, but I was just trying to understand the differences in performance between the various Hobie models, as well as the max speed under reasonable wind conditions. It may affect my next Hobie purchase. I currently own an '88 H17SE with an aftermarket jib package from Calvert. I bought it used a few years ago, and have been happy with it, but it is hard to get a wife and 4 kids on, so I am considering looking for a 21 SE or 21 SC. I like many of the features of the SC, but I am concerned that it may seem slow, compared to my 17, or more importantly, to my brothers' 16 & 18.
Happy Racing!
Author:  xanderwess [ Wed Aug 13, 2008 7:32 am ]
Post subject: 
Wow, I didn't know there was going to be a quiz today.......
Author:  J_Eaton [ Wed Aug 13, 2008 8:10 am ]
Post subject: 
Somewhat of a snapshot of speed comparison is available in US Sailing's Portsmouth Handicap rating table for multihulls

http://www.ussailing.org/portsmouth/tables08/tables08mh.asp

lower number, faster boat...on a race course anyway
Author:  Inland Sailor [ Mon Aug 18, 2008 9:24 am ]
Post subject: 
J_Eaton:

Thanks for the reply, this data basically answers my question. Now all I need to do is decide if I want the fastest boat on the water and if I am willing to pay for it.

Thanks.
Author:  JohnMcBride [ Tue Aug 19, 2008 7:36 pm ]
Post subject: 
Dang, the Aquacats don't have portmouth numbers!

Thank God.
Page 1 of 1 All times are UTC - 8 hours [ DST ]
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/