I had quite a good session with these shots ;-) and managed several keepers starting with this one... Thanks for looking Steve
Set up info: Used a black enamel oven dish for the blue coloured water and placed a mirror in the water below the drop.to bounce some light. Food dye used to colour the water. Dropped from a height of 500mm. The two drops were about 45ms apart (but this really is an approximation) For lighting see strobist info below..
Strobist info: MT24Ex Flash used with flash A Top left bounced off reflector at 45deg. into dark blue water, flash B on RH side 2'o'clock at overhead reflector, both heads on 1/32, ISO320, 2 seconds exposure, F29