I shot 80 and 100 yards today with the club and its amazing how much better I could've done at the comp if I'd had just one practice session beforehand. By the way, I'm not sure if you literally mean sight marks or just aiming markers in general, but just to let you know I'm shooting barebow.
I'm not even having to aim at the sky with my bow as people were saying earlier. For 100 yards,with an under the chin anchor I'm aiming the arrow tip about a third of a boss height above the top of the boss. For 80 yards I switch to 3 under as I'm more comfortable that way, whilst maintaining an under the chin anchor, and I aim at about the black ring on the target, above the gold.