Optical photometry of the UCM lists I and II - I. The data

We present Johnson B CCD photometry for the whole sample of galaxies of the Universidad Complutense de Madrid (UCM) Survey Lists I and II. They consti tute a well-defined and complete sample of galaxies in the Local Universe w ith active star formation. The data refer to 191 SO to Irr galaxies at an a veraged redshift of 0.027, and complement the already published Gunn r, J a nd K photometries. In this paper the observational and reduction features a re discussed in detail, and the new colour information is combined to searc h for clues on thee properties of the galaxies, mainly by comparing our sam ple with other surveys.