General Ocean Turbulence Model (GOTM)

GOTM is an ambitious name for a one-dimensional water column model for marine and limnological applications. It is coupled to a choice of traditional as well as state-of-the-art parameterisations for vertical turbulent mixing. The package consists of the FORTRAN90 software, a number of idealised and realistic test cases, and a scientific documentation, all published under the GNU public license. GOTM is, of course, not complete (and will never be). Whoever is missing any feature in GOTM, is warmly invited to contribute to GOTM and add her or his personal preferences or needs.

http://www.gotm.net/index.php

General Estuarine Transport Model (GETM)

GETM is a 3D numerical model simulating the most important hydrodynamic and thermodynamic processes in natural waters. The model is general in the sense that it can be applied to various systems, scales and specifications. The model includes for example flooding and drying of tidal flats, flexible vertical and horizontal coordinate systems, different turbulence models integrated from GOTM, and is a Public Domain model published under GNU Public Licence.

http://www.bolding-burchard.com/html/GETM.htm