The Fuller Number

Originally posted by AlexM Have you just proved the RYA numbers correct?

No, I have assumed they are correct and fitted an empirical equation that matches reasonably well.
What struck me was the simplicity of it.

The Europe and Pico/topper struck me too.

It could be useful for new classes like the Aero and Zero, because the RYA won't make a guess on a number and the builders will not be trusted whatever number they suggest.

OK, so, I need to know how you''re inputing the data, length in mtrs? sail area sq mtrs?, what crew weight did you use for your chart? Or did you just run with given all up weight or hull weight.

I'm also doubting it if you're using the data as it currently stands, (Looking at my 4 favourite wrong uns, Blaze Phantom, Laser, EPS. and the Streaker/ Solo anomaly.

Edited by iGRF - 22 Apr 14 at 8:17pm

Length in metres, area in square metres and weight in kg, for all up weight including crew. I split boats into needing big, average, small or v small crew at 95, 80, 65 and50kg respectively.
Getting good data is tricky, for example it isn't always clear whether boat weight is just the hull or the whole thing. If anyone has any data, I'll gladly run the numbers. With better and more data, the 144, 37 and 1.2 coefficients will change for the better too.

Now I know what I'm doing, the formula can be calculated in the blink of an eye - I just need lots of good data!

Originally posted by Jeepers If it changes my PY from what I think it should be....I'll sue! ...:)

I'll give you the name of some lawyers my club are talking to..

Originally posted by iGRF How are you expressing the lengths?

I got reasonable answers with metres (and decimals), square metres and kg respectively. For my PlusPlus I entered
4.27     12.5     170
and got 926.62, which was pretty close to my original estimate.


Edited by JimC - 22 Apr 14 at 8:58pm