I need a water script that will say you crashed when you hit it

Just that

@fuzzle_
Thanks. Should I mention you in my game credits

Place a box collider over your water. Make sure the water has a Rigidbody component, and check the Constraints checkboxes for all axis for position and rotation. You can then used the callback OnCollisionEnteron your water script to react to objects crashing into your water, such as displaying a canvas with your text on it.

Make sure that whatever crashes into your water also has a collider and a rigidbody

First place a collider on the water body with isTrigger checked and add a rigidbody component, tick all the checkboxes in the constraints and add a script in the water body as follows :-

using UnityEngine;
...

public class Water : MonoBehaviour
{
     ...
     private void OnTriggerEnter (Collider collider)
     {
           if (collider.gameObject.CompareTag ("hit"))
           {
                 Debug.Log ("Water hit");
           }
     }
}

Also make sure that the object that will collide with water also has a rigidbody and a collider and tag as “hit”. You can modify according to you.