Many gamma-ray burst counterpart searches are being conducted in the
optical-UV band. To both predict detectability and understand the meaning of
any detections or upper limits, we extrapolate gamma-ray spectra from 54 bright
gamma-ray bursts to optical-UV energies. We assume optical emission is
concurrent with gamma-ray emission and do not consider quiescent or fading
counterparts. We find that the spectrum must be steeper (greater flux at low
energy) than a simple extrapolation of the gamma-ray spectrum for more than one
simultaneous optical flash to be observable per year by current searches.Comment: 18 pages including 4 figures, AASTeX 4 (including EPSF), to be
published in Ap.