How to make admin boundary cut off at water

[Anonymous User]

I have a polygon for an administrative boundary, which is on the coast of an island. The admin boundary currently wraps around the coastline polygon I have, but I want it to just stop and not show the border overlapping the coastline.

I have attached an illustration below of what I want to do. I am using ArcGIS Pro 2.9.1

Thanks in advance!

[KimGarbade]

You could try 

https://pro.arcgis.com/en/pro-app/2.8/tool-reference/cartography/set-control-point-at-intersect.htm

If the problem is that the boundaries do not match and one will "Show around" the other, you could do a bunch of things.  Using topology to edit the boundaries so they are shared would be a good one. 

Drastic solutions would include editing COPIES of one or the other or both files. If you want to convert your admin polygons to lines and edit them by deleting the island boundary parts I would probably use Union and Polygon to Line and then edit at will, but you'll lose your polygon topology in favor of a good looking map..