| Carrier Code | Carrier Name |
| WTTU | WARDELL TRANSPORT LTD |
| WTWG | WESTERN TOWING CO |
| WVIU | WEST VAN INC |
| WVMA | WEAVER MARINE AGENCIES LTD |
| WWKW | WORLDWIDE TANKERS INC |
| WWLU | WILHELMSEN LINES AS |
| WWND | WESTWIND SHIPPING PANAMA S A |
| WWRD | WESTWARD MARITIME CORPORATION |
| WWSG | WORLDWIDE SHIPPING COMPANY S A |
| WWSU | WESTWOOD SHIPPING LINES INC |
| WXIU | WORLD CONTAINER LEASING INC |
| XANT | XANTHI SHIPPING CORPORATION |
| XCTU | XTRA CORP |
| XPTC | XPERT TRAFFIC CORP |
| XRRU | XTRA INC |
