World Sea Ports
| Port Name | Port Code | Country Name |
|---|---|---|
| Mapleton | USXUY | United States of America (the) |
| Maputo | MZMPM | Mozambique |
| Mar del Plata | ARMDQ | Argentina |
| Marabá | BRMAB | Brazil |
| Marabahan | IDMAR | Indonesia |
| Maracaibo | VEMAR | Venezuela (Bolivarian Republic of) |
| Maracena | ESMRN | Spain |
| Maragogipe | BRMAR | Brazil |
| Marambio | AQMRB | Antarctica |
| Marano Lagunare | ITMAJ | Italy |