Use a good grade, like dupont, urethane paint. It doesn't mind being in the water and will last and look good for a long time. Preping is the biggest part of painting glass boats. Use a good self sealing and self etching primer.
You can get a clear coat base coat also but from what i have painted it doesn't last as long on glass exposed to water the way we fish but the urethane does.
You can also opt to use the wet look hardner with the paint and it makes the shine come out more.
