  We use an empirical relation to measure the HI scale height of relatively HI
rich galaxies using 21-cm observations. The galaxies were selected from the
BLUEDISK, THINGS and VIVA surveys. We aim to compare the thickness of the HI
layer of unusually HI rich with normal spiral galaxies and find any correlation
between the HI scale height with other galaxies properties. We found that on
average the unusually HI rich galaxies have similar HI disk thickness to the
control sample and the galaxies selected from the THINGS and VIVA surveys
within their uncertainties. Our result also show that the average thickness of
the neutral hydrogen inside the optical disk is correlated with the atomic gas
fraction inside the optical disk with a scatter of ~ 0.22 dex. A correlation is
also found between the HI scale height with the atomic-to-molecular gas ratio
which indicates the link between star formation and the vertical distribution
of HI which is consistent with previous studies. This new scaling relation
between the HI scale height and atomic gas fraction will allow us to predict
the HI scale height of a large number of galaxies but a larger sample is needed
to decrease the scatter.
