Move object on way points in unity3d

ObjectMovmentOnWayPoints.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class ObjectMovmentOnWayPoints : MonoBehaviour
{
    #region Vars

    public List<GameObject> movmentWayPoints;

    public float moveSpeed = 2f;

    [Tooltip("Beginning Wait Time")]
    public float initialWait = 5;

    [Tooltip("Wait time at every waypoint")]
    public float waitAtEveryPoint = 3f;

    public bool isLoop = true;

    float distance;

    private GameObject ship;
    [Header("At after what distance move to next point")]
    public float distnaceThreshold = 22;

    #endregion Vars

    void Start()
    {
        ship = this.gameObject;
        StartCoroutine(MoveOnWayPoints());
        if (movmentWayPoints.Count == 0)
        {
            Debug.LogWarning("There is no movment point, ship will not start to sail");
        }
    }



    IEnumerator MoveOnWayPoints()
    {
        yield return new WaitForSeconds(initialWait); //inital wait

        for (int i = 0; i < movmentWayPoints.Count; i = GetNewIndex(i))
        {
            yield return new WaitForSeconds(waitAtEveryPoint);//Wait at every point

            GameObject movmentTarget = movmentWayPoints[i].gameObject;
            Vector3 destinationDirection = movmentTarget.transform.position - ship.transform.position;

            distance = Vector3.Distance(ship.transform.position, movmentTarget.transform.position);

            while (distance > 22f)
            {

                Quaternion lookRotation = Quaternion.LookRotation(destinationDirection);

                ship.transform.rotation = Quaternion.Lerp(ship.transform.rotation, lookRotation, Time.deltaTime * 2f);
                ship.transform.Translate(new Vector3(0f, 0f, Time.deltaTime * moveSpeed));

                distance = Vector3.Distance(ship.transform.position, movmentTarget.transform.position);

                yield return new WaitForEndOfFrame();
            }
        }

    }

    int GetNewIndex(int lastIndex)
    {
        if (isLoop == true)
        {
            if (lastIndex >= movmentWayPoints.Count - 1)
            {
                lastIndex = 0;

            }
            else
            {

                lastIndex++;
            }

            return lastIndex;
        }
        else
        {
            return lastIndex++;
        }
    }
}