  We update and extend the results of Shanks (1997, MNRAS, 290, L77) by making
a direct test of Tully-Fisher distance estimates to thirteen spiral galaxies
with HST Cepheid distances and to ten spiral galaxies with Type Ia supernova
(SNIa) distances. The results show that the Tully-Fisher distance moduli are
too short with respect to the Cepheid distances by 0.46+-0.11mag and too short
with respect to the SNIa distances by 0.49+-0.18mag. Combining the HST Cepheid
and the best SNIa data suggests that, overall, previous Tully-Fisher distances
at v~1000 kms-1 were too short by 0.43+-0.09mag, a result which is significant
at the 4.6 sigma level. These data therefore indicate that previous
Tully-Fisher distances should be revised upwards by 22+-5% implying, for
example, a Virgo distance of 19.0+-1.8Mpc. The value of Ho from Tully-Fisher
estimates is correspondingly revised downwards from Ho=84+-10kms-1Mpc-1 to
Ho=69+-8kms-1Mpc-1. There is evidence that the Tully-Fisher relation at large
distances is affected by Malmquist bias. In this case, we argue that
Ho<50kms-1Mpc-1 cannot be ruled out by Tully-Fisher considerations.
