Sea around terrain,Do a sea for terrain

I have been triying to add sea to my terrain , like the standard assets one. The problem is that if I use the standard assets one in such a big terrain my computer might explode. I am also looking for other ways of doing sea than a water plane. Could you please recommend me any videos or information that I might find helpful?
Thanks in advance!,I have been triying to do a water plane like the standard assets one but much larger ( cover a terrain ) and I dont know exactly how to do it without forcing my computer to explode. Could you please recommend me any videos or documentation that might help me?
Thanks in advance!

the cheapest splution is a plane with a water shader. but i do not know what you’re target is.

have a look at githubb there are many water solutions for free. if you want to buy something you might want to buy aquas.