  We have carried out targetted sub-mm observations as part of a programme to
explore the connection between the rest-frame UV and far-IR properties of
star-forming galaxies at high redshift, which is currently poorly understood.
On the one hand the Lyman break technique is very effective at selecting z~3
galaxies. On the other hand `blank field' imaging in the sub-mm seems to turn
up sources routinely, amongst which some are star forming galaxies at similar
redshifts. Already much work has been done searching for optical
identifications of objects detected using the SCUBA instrument. Here we have
taken the opposite approach, performing sub-mm photometry for a sample of Lyman
break galaxies whose UV properties imply high star formation rates.
  The total signal from our Lyman break sample is undetected in the sub-mm, at
an RMS level of 0.5 mJy, which implies that the population of Lyman break
galaxies does not constitute a large part of the recently detected blank-field
sub-mm sources. However, our one detection suggests that with reasonable SCUBA
integrations we might expect to detect those few LBGs that are far-IR
brightest.
