Is there a trick to making a large scene that is not really large?

For example....lets say i had a scene with a ocean, clouds generated in a 3d box, and a high poly boat zipping around....and i want to in my video fly in on it with the camera and kind of circle around the boat.

Well you want the clouds and ocean to keep going on...not being cut off....so would i make a really huge ocean and sky? Or is there a camera scaling trick or LOD on the ocean and clouds....because I'de imagine having so much ocean and clouds would really tax your computer