  We investigate the properties of the B-band Tully-Fisher (T-F) relation for
25 compact group galaxies, using Vmax derived from 2-D velocity maps. Our main
result is that the majority of the Hickson Compact Group galaxies lie on the
T-F relation. However, about 20% of the galaxies, including the lowest-mass
systems, have higher B luminosities for a given mass, or alternatively, a mass
which is too low for their luminosities. We favour a scenario in which outliers
have been brightened due to either enhanced star formation or merging.
Alternatively, the T-F outliers may have undergone truncation of their dark
halo due to interactions. It is possible that in some cases, both effects
contribute. The fact that the B-band T-F relation is similar for compact group
and field galaxies tells us that these galaxies show common mass-to-size
relations and that the halos of compact group galaxies have not been
significantly stripped inside R25. We find that 75% of the compact group
galaxies studied (22 out of 29) have highly peculiar velocity fields.
Nevertheless, a careful choice of inclination, position angle and center,
obtained from the velocity field, and an average of the velocities over a large
sector of the galaxy enabled the determination of fairly well-behaved rotation
curves for the galaxies. However, two of the compact group galaxies which are
the most massive members in M51--like pairs, HCG 91a and HCG 96a, have very
asymmetric rotation curves, with one arm rising and the other one falling,
indicating, most probably, a recent perturbation by the small close companions.
