Check out WRCRA
just south of Annapolis. They race all kinds of cats there and most of the guys have been doing it a while. I sold my Hobie 18 to a member of the club. I've never sailed a Nacra but I imagine they sail similarly to the Hobie's. If the 5.0 has a jib I highly suggest the following steps for tacking:
1) If needed fall off slightly to gain speed
2) As you come up to tack, slowly bring in the main until it is centered
3) Leave the jib backwinded
4) Throw the tiller around the back side of the mainsheet as you move to the new windward side of the boat
5) Leave the jib backwinded until the main battens pop across
6) Sheet the main out about 12"
7) Tack the jib
8) Adjust both sails for the new coarse
You will blow lots of tacks. there is very little inertia on these boats so it can be frustrating. Once you get the hang of tacking it will only a few seconds. Not as fast as a mono dinghy but it will be pretty quick. If you have any more questions, pm me and I can try to answer them. Also, check out the Beachcat forum
. Many very knowledgeable sailors there.