Carbon Fibre has been a real boon to the racing dinghy sailor.  It's long lasting properties ensure that the inital higher cost of a spar is easily offset by a long life span.

Add to this is the ability of a carbon spar to be modified to suit the needs of the sailor. Be it in the bending characteristics for Finn or OK masts (see here), or the addition of stiffening in selected places to control mast flexing in stayed masts.

Carbon fibre masts can suffer incredible abuse before failure, however they must be repaired as and when problems arise.  The motto for carbon spar owners is "eternal vigilance".

Inspect the spars frequently and get damage fixed before there is a break. While broken carbon fibre masts can be repaired (see here), it is better to fix before they break.