What tools are available to build unstructured grids for ocean models? Generating finite element/volume grids is tricky, especially when you are dealing with complex coastlines. What are the more common tools to create the grids and to check the quality (e.g., minimum angles, wave propagation constraints) of it?
The simplest is triangle http://www.cs.cmu.edu/~quake/triangle.html which is providing lib form many other more advanced packages. You can create poly file and create "holes/islands" in grid etc. Easy to make simple grids.
Another more advanced / gui is xmgredit where you can create/modify grids.
Blue kenue  etc.. 
use the force luke, do a google and it will popup many other packages,
I just wrote a few which are free and for 2D ocean applications.