Underwater Effect Help

I Am A Kind-Of Noob To Unity Scripting, And I Need Help. Can Anyone Help Me Write A Script, Where When The Character's Camera Is On Level With Or Under The Water, Bluish Fog Appears. And If Possible Without Shaders. Here Is My Script So Far:

using UnityEngine; using System.Collections;

public class UnderWater : MonoBehaviour {

 public Camera cam;
 private float campos;
 public GameObject player;

 void Start() {

     campos = cam.transform.position.y;

 }
 

 void OnTriggerEnter(Collider other) {

     if(other.name == "MainCamera"){
         

         if (other.transform.position.y -= this.transform.position.y) {



         }

 

 }

} }

Please Help Me Finish It.

-TCE