Sorry to say but I'm not having much luck finding a regatta for us to do. Best so far is the Peter Loft Marathon from my old club at Bayview on the 6th May, http://www.byra.org.au/events/peter_loft.php
. It's an end of season race down Pittwater, about a mile of open estuary crossing round Lion Island then back to the shelter of Pittwater and on to the club, about 20km total. Many different classes involved and a fun day usually.
I'll keep looking for something in Feb/March. There's heaps on for Australia Day but it's not a long weekend this year and I'll be in Geelong.