F18 crew weight limits

I am currently re-rigging my Nacra 6.0 NA with Calvert sails screecher etc as my first move to get back into competitive one design cat racing (get fit, have fun, make the kids/ wife happy) but am wanting ultimately to move down to F18 as that seems the place to be. Will keep the Nacra of course.
Question re F18:
1. What are the specific rules for crew weights/ adjusters?
I am 240 and crew is 115. Can we be competitive and how does the adjustment work (if at all!). I have searched for an answer but am still a little unclear. Please advise.
2. There will be a second question and a 3rd depending on the answer to the first.

There are two weigh ranges

Under 309 and over 309lbs

If you are under 309 you will be using a small sailplan. If you are under 285 you will have to carry weight equal to 1/2 the difference of your weight subtracted from 285.

If you are 309 or up you are allowed to sail the big sail plan, you are always allowed to sail with the small sailplan though. If you are on the big sailplan and your weight it above 309 and under 330 you carry weights equal to half the difference of your weight subtracted from 330lbs. Above 330 you are good to sail with either the small or large sailplan.

Dan

At 355 of crew weight, you'll love the boat in anything over 12 knots, unless you're a glutton for light air like me. The boat does perform well with that weight, especially once you're double trapped - others around you will be depowering in the mid-teens while you are coming into your best performance band. At around 320, my skipper and I carry crew corrector weight and hit the bottom of the cunningham somewhere around 13 knots.

Thanks. I had understood this in general terms but wanted to see the specifics.
Cheers
H

The full doc is located here: http://www.naf18.com -> rules

Excellent.
Thanks.