Last weekend broke in two halfs dageerboard of my Nacra Inter 18. Due to the lack of Nacra dealers in Russia, I'll appreciate any idea how to repair it or get used or new board on decent price.
Regards,
Nail

if it broke left half, right half you might get away using epoxy to put it back together

but if you mean top half, bottom half you'll need to

1) buy new - very expensive i guess
2) buy used - might be very hard to find, but i seem to remember a dutch cat breaker who may have more nacra stuff that most
3) get 1 made by someone who knows their stuff, carbon over foam core?
4) knock something up yourself from carefully planed, sanded plywood and then wrap it in several layers of glass and epoxy, then filler and sand it smooth for gelcoat or paint

http://www.catamaranparts.nl/

http://2ehands.nacrasailing.com/dealers.php#37

Depends on the damage. You can have a look here to see how I did it.

http://multimani.blogspot.com/2007/06/noe-glassfiberarbeide.html

Sand a nice taper down to the break.
Glue the parts together. You need to glue it back together in a jig to keep it straight and aligned!
Put on new glass. 0 - 90 and +-45 deg to the break.
Do a good job and it is stronger than it used to be.

If you have an internal spar in the daggerboard, it gets more complex and investigating doing a mold off the remaining daggerboard to build a new one becomes attractive.

Good luck.