A new chapter 7 has been added to report KD 598 about the VIRYA-0.65 floating water turbine. In this chapter it is investigated if the matching in between rotor and generator can be improved by taking a simple 2-bladed rotor with a slightly smaller rotor diameter of 0.625 m in stead of 0.65 m and a design tip speed ratio of 3.5 in stead of 3. The matching of this VIRYA-0.625 for 26 V battery charging and star rectification of the original 230/400 V winding is better than for the VIRYA-0.65. The better matching results in reduction of the cut-in water speed from 0.7 m/s to 0.6 m/s. The starting water speed is increased from 0.37 m/s up to 0.5 m/s but, as it is still lower than the cut-in water speed of 0.6 m/s, this is no problem. The maximum power at V = 2 m/s is 160 W, so the same as for the VIRYA-0.65. The negative effect of the slightly smaller rotor diameter is compensated by the better matching.