| Potomac to Santarem | 3,577.81 mi (5,757.93 km) |
| Potomac to Santiago do Cacem | 3,610.63 mi (5,810.75 km) |
| Potomac to Santo Andre | 3,607.21 mi (5,805.24 km) |
| Potomac to Santo Tirso | 3,533.42 mi (5,686.49 km) |
| Potomac to Sao Bras de Alportel | 3,676.07 mi (5,916.06 km) |
| Potomac to Sao Felix da Marinha | 3,533.50 mi (5,686.62 km) |
| Potomac to Sao Joao da Madeira | 3,543.51 mi (5,702.73 km) |
| Potomac to Sao Joao de Ver | 3,539.04 mi (5,695.53 km) |
| Potomac to Sao Mamede de Infesta | 3,530.37 mi (5,681.59 km) |
| Potomac to Sao Pedro do Sul | 3,567.79 mi (5,741.80 km) |
| Potomac to Satao | 3,584.37 mi (5,768.49 km) |
| Potomac to Seia | 3,594.09 mi (5,784.13 km) |
| Potomac to Senhora da Hora | 3,528.26 mi (5,678.19 km) |
| Potomac to Serpa | 3,667.39 mi (5,902.09 km) |
| Potomac to Serta | 3,591.32 mi (5,779.67 km) |
