I need to faceting and make some grammar's style to a temperature-salinity (TS) diagram and using the OCE package is not the solution. Everything can be done quite easily by using the ggplot2 package, except (as far as I know) for the incorporation of isopycnal lines. I have the isopycnals calculated from the function DrawIsopycal() and from our own database, but I haven't figure out yet hot to implement there inside ggplot2, any suggestion?