Yes sir,
I did, that gives me Vessels with all CustomerID's (All vessels actually)
I changed my RowSource to this:
SELECT [VesselT].[VesselID], [VesselT].[Vessel IMO (Vessel Table)], [VesselT].[Vessel Name], [VesselT].[CustomerID] FROM VesselT WHERE [VesselT].[CustomerID] =...