In this talk I will address two main topics involving extensive HI and optical surveys of the nearby Ursa Major cluster. In the first part I will present results from a Westerbork HI survey of pointed observations aimed at gaining a better understanding of the statistical properties of the Tully-Fisher relation by using detailed kinematic and photometric information of individual galaxies. I will show that the near-infrared TF relation has a slope of -10 and a scatter consistent with the measurement errors when using the dark matter dominated amplitude of the outer flat part of the HI rotation curves. In the second part I will talk about a blind VLA HI survey of Ursa Major aimed at 1) determining the slope of the HI mass function at the low-mass end down to HI masses of 10^7 Msun and 2) testing the hypothesis that High Velocity Clouds might be intergalactic. The main result is that the HIMF turns out to be flat at the low-mass end while no intergalactic HVCs are detected. All new HI detections have optical counterparts while the optically selected cluster candidates that are not detected in HI are generally of the dwarf spheroidal type. Spectacular HI filaments are discovered to be associated with the brightest lenticulars in the cluster.