So..there have been a few comments in the past about P323 boat speed and polar charts. Sadly Pearson (AFAIK) was not much help with this.
A couple of years ago I came across a spreadsheet program called PCSail developed by a student at the University of Michigan. Sadly it needs a really old version of excel to work - 2003, I think - and so I can't get it going on my current PC (and vbasic experts out there?). Full download can be found here:
http://www.cruisersforum.com/forums/f134/pcsail-excel-sheet-to-make-vpp-for-sailing-yachts-89998.html.
Anyway, before my old version of excel became unusable, I developed a rough polar chart, and a speed table - which holds up pretty well for me (for data fiends I can post my assumptions upon request). I keep this table in my cockpit so I can check if my sail trim is optimal. For your edification, here is is:
Selene Wind Jib size
(kts) 87% 99%
Max VMG
~40º (Close hauled)
5 3.2 3.4
7 4.2 4.3
10 5.1 5.2
14 5.7 5.7
19 5.9 5.9
65º (Close Reach)
5 3.9 4.0
7 5.0 5.1
10 6.1 6.2
14 6.7 6.7
19 7.0 7.0
90º (Beam Reach)
5 3.8 4.0
7 4.9 5.1
10 6.1 6.2
14 6.8 6.8
19 7.0 7.0
120º (Broad Reach)
5 2.5 2.6
7 3.4 3.5
10 4.6 4.7
14 5.8 5.9
19 6.7 6.7
178º (running/DDW)
5 2.1 2.2
7 2.9 2.9
10 4.0 4.1
14 5.4 5.4
19 6.6 6.6