defining boundary conditions

hey everyone,
I am a new MIKE 21 user, so I apologize for asking this simple question.... BUT how do I define my boundaries once I have my mesh?
Basically, I want to set up one open boundary with incoming waves, etc. and 3 closed or land boundaries.
Can anyone offer any suggestions? Thanks!

Which MIKE21 do you use ?

MIKE21 Grid or Flexible mesh?

In the grid Version, boundaries can only be defined on the border cells of your grid. That means, that at lieast one boudary part of the defined model must not be defined as land value.

In the Flexible Mesh you define your boundaries by means of code values. You can open your mesh - File in the data Manager and define different code values. Those code values are then accessible in the boundary section of the MIKE21.

Bests Christian

Thank you! Yes MIKE 21 Grid Generator.  I was actually able to define my boundaries in the Grid Generator using the Codes and successfully ran my first simulation.  So I am making some progress! Thank you!