  The Tully-Fisher relations for a complete sample of spirals in the Ursa Major
cluster is investigated. The merits of combining B, R, I and K' photometry with
HI rotation curves (RCs) have been exploited. In addition to the corrected HI
global profile widths W_{R,I}^i, the HI RCs allow direct measurements of the
maximum rotation Vmax and the amplitudes Vflat of the outer flat parts. The
dynamical state of the gas disks could also be determined in detail. For large
galaxy samples, the M^{b,i}_R - Log(W_{R,I}^i) correlation in conjunction with
strict selection criteria is preferred for distance determinations with a 7%
accuracy. Galaxies with rising RCs at the last measured point lie
systematically on the low velocity side of the TF-relation. Galaxies with
partly declining RCs (Vmax>Vflat) tend to lie on the high velocity side when
using W_{R,I}^i or Vmax. These trends are eliminated when Vflat is used. The
M^{b,i}_B - Log(2Vflat) residuals correlate consistently with morphology,
color, surface brightness and gas mass fraction. These correlations are absent
for the near-IR M^{b,i}_K' - Log(2Vflat) residuals. The tightest correlation
(Xred=1.1) is found for the M^{b,i}_K' - Log(2Vflat) relation with a slope of
-11.3 +/- 0.5 and a total scatter of 0.26^m with a most likely intrinsic
scatter of zero. The tightness of the near-IR correlation is preserved when
converting it into a baryonic TF-relation which has a slope of -10.0 for
(Mgas/L_K')=1.6 while a zero intrinsic scatter remains most likely. The
tightness of the near-IR and baryonic correlations suggests that the
TF-relation reflects a correlation between the dark matter halo mass, indicated
by Vflat, and the total baryonic mass Mbar where Mbar~Vflat^4. The distribution
of the baryons inside halos of similar mass is irrelevant for this relation.
