Extending a polygon outwards?

Question

Hi everyone

I was wondering if there was a way to extend a polygon outwards?
What I have is a polygon of a country with 12 different regions within it and the edge (coast) is lined with these various regions (no region overlaps). I wish to extend these polygons 30m past the coastline. However I can't use a buffer(with the outside only option) because then the regions overlap and it's impossible to clip overlaps when at different points of the coastline, I have different regions overlapping. I also can't use the edit vertices option because there are so many vertices that I would have to individually click and drag outwards to the same distance. Is there a function that can take my polygon and extend the polygon outwards over the coast?

Thanks

KirstenLukeACJV · Answer

I need to do this exact thing, too, for all counties along the US Atlantic Coast. Any other suggestions?  I need  this so I can use a county layer for zonal summaries...my rasters mostly extend slightly offshore to the coast boundary.

SanwaraneeKarunaratne · Answer

Yes I had set a search distance of 30m and tried to do the join to the closest region but the processing time wasn't practical. 
Ordinarily simplifying would be great but I have to keep the level of accuracy high for this particular project.

DarrenWiens2 · Answer

Oh, I think I see. When you tried Spatial Join, did you set a search distance? That can make a big difference. Something else you could try is running Near to find the closest polygon to each point, then join them together (not sure if that would be any faster). You could also make a simplified version of your coastline polygons and try Spatial Join to that.