control how the mesh grows

[BjornAlmstrom]

Hi (again)
I wonder if there is any way to control how the mesh "grows". I want to have small mesh-size at depths smaller than 6 m (and I want them all to be the same size), and that works with qgis-gmsh. However, these triangles then grows very slowly and expands too far in the seaward direction, resulting in a too many triangles in my mesh.

Best regard,
Björn