  We scan the parameter space of the NMSSM for the observability of a Higgs
boson at the LHC with $300 {\rm fb}^{-1}$ integrated luminosity per detector,
taking the present LEP constraints into account. We focus on the regions of
parameter space for which none of the usually considered LHC detection modes
are viable due to the fact that the only light non-singlet (and, therefore,
potentially visible) Higgs boson, $h$, decays mainly to two CP-odd light Higgs
bosons, $h\to a a$. We simulate the $WW\to h \to aa$ detection mode. We find
that this signal may be detectable at the LHC as a signal/background $\sim
600/600$ bump in the tail of a rapidly falling mass distribution. If further
study gives us confidence that the shape of the background tail is predictable,
then we can conclude that NMSSM Higgs detection at the LHC will be possible
throughout all of parameter space by combining this signal with the usual
detection modes previously simulated by ATLAS and CMS. We also show that this
$WW\to h\to aa$ signal will be highly visible at the LC due to its cleaner
environment and high luminosity. We present a study of the production modes and
decay channels of interest at the LC.
