  Hughes & Gaztanaga (2001, see article in these proceedings) have presented
realistic simulations to address key issues confronting existing and
forthcoming submm surveys. An important aspect illustrated by the simulations
is the effect induced on the counts by the sampling variance of the large-scale
galaxy clustering. We find factors of up to 2-4 variation (from the mean) in
the extracted counts from deep surveys identical in area (6 sqr arcmin) to the
SCUBA surveys of the Hubble Deep Fields (HDF). Here we present a recipe to
model the expected degree of clustering as a function of sample area and
redshift.
