A quick way to tell if it's VC or a similar Petit product is to take a rag dampened with alcohol and wipe a spot. The spot will have a copper shine. It's great bottom paint in fresh water, useless in saltwater. More than likely, the bottom paint will have to be stripped or media blasted before changing paint.
When investigating a replacement, remember that many bottom paints are not formulated for boats that are stored on trailers. They lose their effectiveness if they are out of the water for any length of time. In addition, ablatives will scuff off as the bottom is dragged across trailer bunks and rollers.