Dear you! Description of task: I am now using RMA2 with SMS 10.0 to model a relative complex area close to a river mouth. For simplicity, I regard the water flow from the river as constant. There are 4 fjord arms outside the river, from where I do have current measurements to force the model. I do find a strong tidal signal. I choose to put given tidal elevation data given from public available tables at the outermost oceanic boundary, towards the ocean, to be consistent with the recommended way of running RMA2. Comment: I do have to manually adjust the BC-files, where the current switches direction, and add the value of "pi" to the angle. I reckon this must be a straightforward task for the RMA-designers to improve!?! Question: I do model only the surface layer, say the upper 10 meters. I calculate the water fluxes of the 3 boundaries and assign them as BCs (current * area). Then I wonder if it is correct to use the whole tidal elevation amplitude for the water surface elevation forcing, or only a fraction of it? I am modelling only the upper 10 meters out of a total depth of about 100m. Do you have any guidelines or mathematical approach to answer this question? Hope anybody is able to help! Best regards Leikvin