Underwater Blur Effect Help

Hey, I'm testing out my underwater blur and it's not working, can someone tell me why?

I get this error : Underwatersrc.cs(12,15): error CS0103: The name `underwaterblurt' does not exist in the current context

Here's the code

 using UnityEngine;
 using System.Collections;
 
 public class Underwatersrc : MonoBehaviour {
     public AudioClip Underwatersound;
     
     
     void Blureffectunderwater(){
     BlurEffect underwaterblur = Camera.main.gameObject.GetComponent (typeof(BlurEffect)) as BlurEffect;
           if(underwaterblur == null)
           {
               underwaterblur = Camera.main.gameObject.AddComponent(typeof(BlurEffect)) as BlurEffect;
               underwaterblur.iterations = 2;
               underwaterblur.blurSpread = 0.2f;
               underwaterblur.enabled = true;
               
           }
     }
     
     
     void Update() {
         
         if(Camera.main.transform.position.y < 26){
         RenderSettings.fogMode = FogMode.Exponential;
         RenderSettings.fog = true;
             RenderSettings.fogDensity = 0.085f;
             RenderSettings.fogColor = new Color (0.22f, 0.65f, 0.77f, 0.5f);
             underwaterblur = true;
             
         }
         else {
             
             RenderSettings.fogMode = FogMode.Linear;
             RenderSettings.fog = true;
             RenderSettings.fogDensity = 0.85f;
             RenderSettings.fogColor = Color.white;
         
             
         }
     }
     
 }