Boat controller help

using UnityEngine; using UnityEngine.UI; using UnityEngine.EventSystems; using UnityEngine.Events; using System.Collections;

public class boat1 : MonoBehaviour {

 public Graphic UI_Element;
 private Rigidbody rbody;
 public Slider rightSlider;
 RectTransform rectT;
 Vector2 centerPoint;
 public float maximumSteeringAngle = 180f;
 float wheelAngle = 0f;
 float wheelPrevAngle = 0f;
 bool wheelBeingHeld = false;
 
 float leftrightThrust;


 public float SubmitSliderSetting()
 {
     return rightSlider.value;
 }

 public float GetClampedValue()
 {
     
     return wheelAngle / maximumSteeringAngle;
 }
 public float GetAngle()
 {
     
     return wheelAngle;
 }

 void Start()
 {
     rectT = UI_Element.rectTransform;
     rbody = GetComponent<Rigidbody>();
     InitEventsSystem();
     UpdateRect();
     
 }

 void Update()
 {   leftrightThrust = GetClampedValue();
     
     Debug.Log((int)wheelAngle);
 }

 void FixedUpdate()
 {
     rbody.AddForce(transform.forward * Time.deltaTime * rightSlider.value, ForceMode.Acceleration);

     transform.Rotate(0, (int)wheelAngle, 0,Space.Self);

    
     rectT.localEulerAngles = Vector3.back * wheelAngle;
 }

 void InitEventsSystem()
 {

     EventTrigger events = UI_Element.gameObject.GetComponent<EventTrigger>();

     if (events == null)
         events = UI_Element.gameObject.AddComponent<EventTrigger>();

     if (events.triggers == null)
         events.triggers = new System.Collections.Generic.List<EventTrigger.Entry>();

     EventTrigger.Entry entry = new EventTrigger.Entry();
     EventTrigger.TriggerEvent callback = new EventTrigger.TriggerEvent();
     UnityAction<BaseEventData> functionCall = new UnityAction<BaseEventData>(PressEvent);
     callback.AddListener(functionCall);
     entry.eventID = EventTriggerType.PointerDown;
     entry.callback = callback;

     events.triggers.Add(entry);

     entry = new EventTrigger.Entry();
     callback = new EventTrigger.TriggerEvent();
     functionCall = new UnityAction<BaseEventData>(DragEvent);
     callback.AddListener(functionCall);
     entry.eventID = EventTriggerType.Drag;
     entry.callback = callback;

     events.triggers.Add(entry);

     entry = new EventTrigger.Entry();
     callback = new EventTrigger.TriggerEvent();
     functionCall = new UnityAction<BaseEventData>(ReleaseEvent);//
     callback.AddListener(functionCall);
     entry.eventID = EventTriggerType.PointerUp;
     entry.callback = callback;

     events.triggers.Add(entry);
 }

 void UpdateRect()
 {
     
     Vector3[] corners = new Vector3[4];
     rectT.GetWorldCorners(corners);

     for (int i = 0; i < 4; i++)
     {
         corners[i] = RectTransformUtility.WorldToScreenPoint(null, corners[i]);
     }

     Vector3 bottomLeft = corners[0];
     Vector3 topRight = corners[2];
     float width = topRight.x - bottomLeft.x;
     float height = topRight.y - bottomLeft.y;

     Rect _rect = new Rect(bottomLeft.x, topRight.y, width, height);
     centerPoint = new Vector2(_rect.x + _rect.width * 0.5f, _rect.y - _rect.height * 0.5f);
 }

 public void PressEvent(BaseEventData eventData)
 {
     
     Vector2 pointerPos = ((PointerEventData)eventData).position;

     wheelBeingHeld = true;
     wheelPrevAngle = Vector2.Angle(Vector2.up, pointerPos - centerPoint);
 }

 public void DragEvent(BaseEventData eventData)
 {
     
     Vector2 pointerPos = ((PointerEventData)eventData).position;

     float wheelNewAngle = Vector2.Angle(Vector2.up, pointerPos - centerPoint);

     
     if (Vector2.Distance(pointerPos, centerPoint) > 20f)
     {
         if (pointerPos.x > centerPoint.x)
             wheelAngle += wheelNewAngle - wheelPrevAngle;
         else
             wheelAngle -= wheelNewAngle - wheelPrevAngle;
     }

     
     wheelAngle = Mathf.Clamp(wheelAngle, -maximumSteeringAngle, maximumSteeringAngle);

     wheelPrevAngle = wheelNewAngle;
 }

 public void ReleaseEvent(BaseEventData eventData)
 {
     DragEvent(eventData);

     wheelBeingHeld = false;
 }

}

As you can see i am trying to make a boat controller and taking angle on the screen with this .

there is 2 propeller on my boat. I want to rotate each of my propeller as wheel angle and push forward or backward effect like real propeller.Of course i am ignoring gravity, friction or too many rules in physics. I just want to change the rotation of my each propeller and make an forward effect on that direction. in 45 degrees of each propeller my ship's ahead goes right or in 90 degrees its effect more and turn right more than 45 degrees because my propeller in 90 degrees. Exactly i am traying to do ASD tugboat controller.

This script added on my rightengine which is a gameobject and it has a ridigbody and mesh collider also connected to the boat with hinge joint.