Problems making canvas larger and keeping resolution

[vitroelsa]

I'm having trouble making the canvas for this webgl code larger, without sacrificing resolution. When I double the resolution its gets choppy and the broswer can't handle.

I can zoom in and turn the angle of the camera but i'd rather zoom in a little, and then make the canvas larger so I don't lose resolution by zooming in too far. If I use CSS and make the canvas larger, the water is just stretched and the resolution looks worse. I want to make the canvas bigger though so I can fill the entire screen with water. Also, when it's large enough when resizing down to mobile as a background.

Any ideas? Here's a screenshot of what I have so far, I just wish the canvas ws larger so I didn't have to zoom in so much.

https://i.stack.imgur.com/ocVXE.png