World Sea Ports
| Port Name | Port Code | Country Name |
|---|---|---|
| Maricá | BRMRC | Brazil |
| Marieberg | SEMAR | Sweden |
| Mariefred | SEMRF | Sweden |
| Mariehamn (Maarianhamina) | FIMHQ | Finland |
| Mariehamn (Maarianhamina) | AXMHQ | Åland Islands |
| Mariel | CUMAR | Cuba |
| Mariensiel | DEMRS | Germany |
| Mariestad | SEMAD | Sweden |
| Marigot | MFMAR | Saint Martin (French Part) |
| Marigot | GPMSB | Guadeloupe |