Error when trying to access a Textbox on a User Control

I created two user controls with different user interfaces. Depending on a selection the user makes, one of these interfaces will be used in my class. Since I don't know until after the user makes a selection, I cannot declare the user control ahead of time so I created a public variable to later assign the correct user control to.

The error occurs when I try to access a control (textbox) on the user control. However, if I declare the user control without assigning it to the public variable, then I don't get an error. Also, if I were to assign the user control to the public variable as its being declared then I don't get an error either. I really do need to be able to pick between the two user controls though. I don't know what to do. Am I missing something? I appreciate any help.

Public Class VesselData
 Public RCAVesselData 
 Public AOLVesselData 

  Public Sub New()
   If Main.UserSelectedModule = "Arrival on Location" Then
    OperatorView = New AOLVesselData 'User Control 1
   ElseIf Main.UserSelectedModule = "Running Conventional Anchors" Then
    OperatorView = New RCAVesselData 'User Control 2
   End If

   OperatorView.txtDistanceToFairlead.text = "A" 'THROWS MissingMemberException - Public member 'txtDistanceToFairlead' on type 'AOLVesselData' not found.
   Dim Test as New AOLVesselData
   Test.txtDistanceToFairlead.text = "A" 'DOES NOT THROW EXCEPTION
  End Sub