The CBOLT project has been moribund for a number of years now. But we may re-birth it.
For inspiration see the document (ACMGIS_2009_Vance.pdf)
Integrating particle tracking models into a GIS for analysis and display of environmental phenomena, Tiffany Vance, Sharon Mesick, Scott Cross (2009).
The software uses 4th order Runge Kutta, with a clever interpolation scheme based on irregular triangular mesh which can be adapted to any hydrodynamic model gridding method, from finite elements...