I saw this video where a scripter had simulated waves with triangles (as parts) and I was wondering how this would perform against smooth terrain water on a large scale?
Aesthetically, I’d appreciate it more than terrain water for the style of game but I’m unsure on how it affects performance.
I don’t think any of you will have an exact answer which is why I’m asking for a rough guess, do you think as a scripter a properly optimised triangle part ocean would perform well or not?
If you only simulate physics at close proximity and waves at a medium distance with a decreasing level of detail, then it would be the same as running a medium complexity game on top of your game.
If you simulate it for an entire map then you could expect FPS close to 0.
That sounds good enough to use. Thank you!
It will run smoothly as long as you do not use parts and only simulate nearby waves. The example you linked uses beams and attachments, not parts (otherwise it would be extremely laggy). If you want help on this you could ask @Spynaz, who created the example you used.
goes to show how little I know about programming 
I won’t need this for an unknown number of months, I’m just adjusting my game plan to what’s viable and the best approach to a task - I didn’t want to plan the ocean elements around this kind of water to find it’s too laggy to be used.