Boat Speed

I have also made the move to an F18 from an i20.

I've only got 2 days sailing on my C2 so far. 0-5 on the windspeed.

I felt our downwind speed was OK, about what I was expecting.
you need to heat it up a bit more than the I-20 then work it down, can't just sail down like the I-20, unless it super super light then settle into low mode even if its slow. If in that low and slow mode and aren't even close to flying a hull pull your boats up about to the strap. Leave boards down to help facilitate flying a hull until the hull in popping up super aggressively that you can't control it with two crew members sitting on windward side."
We really struggled upwind, we lacked height and speed very badly. The boat seemed very sluggish in the puffs, and seemed very slow to accelerate.

My upwind sails are 2010 vintage, but I think they have been heavily used in that time. I have a new jib on order.
"new jib will help pointing a bit. we have 3 traveler car positions, just inside the inside post, centered overed inside post, and just outside the outside post (i dont know if weve actually used that last one). Generally we almost always sail just inside the inside post."
Our mast rake was at the top of the plastic clip above the lower pintle. Rig tension was 110lbs, diamonds were at 450lbs.
"mast rake is correct. Diamond tension 23-28 on loos gauge, tighter as it gets windier. Diamonds 37 base in super light air, 38 in anything over 5 especially if there is chop."
With a crew weight of 350, what should should I start with as a baseline on spreaders and diamonds?
"on 2010 sails they reccomend around 45mm on spreader rake, sam is right the new deeper sails use more spreader rake. If your light air and pointing is hurting try a bit more spreader rake. Personally I used 55 and liked it, tried 50, didn't like it, and went back to 55 and have been there since. We generally sail at around 390 but I sailed America's at 330 at the same. In reality the number is just a base number, you need to figure out the best setting for your sail and crew weight and it can vary largley."
I could be just expecting way too much coming off of an overpowered i20.

Interesting observations on crew weight. If it's lumpy I try to stay right on the front beam, with helm and crew close together. If it is super flat I journey about halfway to the bridles, but not much further than that.

When in doubt, sit further forward.

You keep telling yourself that Sam. That's a very old school thought of catamaran sailing, it's even the way I was taught. These new boats you can definitely sit too far forwards, a couple feet in front of the crossbeam is really max.

Oh you're just a broken old man after realizing you are way to fat and old to crew but I guess that was your epiphany after you drank away your shame for not making it into gold fleet at worlds last year.
But i do honestly have to offer you kudos for giving it a shot, it was very entertaining. I remember one mark rounding in particular where I saw you scurry across the boat so fast and I think it was accompanied by a nice loud fart as you were obviously digging deep. That was only one of two mark roundings I saw you so maybe the rest were better.
Either way, Sam knows what I meant and obviously you are more sensitive than him. You better lay off them hormones.
But you do know I love you just like a grandpa, because you are old enough to be mine.