Ant, registration is between 8-10am on the saturday for the off-the-beach classes, which inlcudes sailboards, so you should be able to enter then and pay an extra $5 (on top of the $25). On-line entry is very easy, and probably the best way to go. Info from the website:
ENTRY CLOSING DATE
Entries close Monday 20th February 2012 and should be accompanied by full entry fees. The Race Committee may accept late entries however a late entry fee of $5 per crew for keelboats and $5 per boat for Off The Beach Classes will apply. Entries may be made in person, by mail, facsimile or online as below Telephone entries are not accepted. Bellerive Yacht Club, 64 Cambridge Road, Bellerive or PO Box 26, Rosny Park 7018. Facsimile No. (03) 6244 4320 Entry forms and online entries are available at
http://crown.belleriveyachtclub.com.au/While the weather is looking pretty good for general sailing on the weekend (finally), it should be awesome for the racing. The Derwent River should get fairly consistent NNE winds and it is generally quite flat from this direction, which is great for upwind downwind racing.
This event is definitely open to all sailboards, not just the Formula boards, and should be a lot of fun. With a bit of wind and flat water, a fast slalom board might be quite competitive!