GREAT boat. Congratulations.
The hull speed is determined by the following formula:
Hull Speed = 1.34 * (Sq. Root of the LWL)
So, the theoretical hullspeed for the A30, with a LWL of 21'8" would be 6.25 knots. You may get a little more when heeled.
If you don't know about it, I would highly recommend checking out the Plastic Classic forum at
www.triton381.com/forum. Sailnet is a great resource, but you'll want to check out the Plastic Classic forum as well.