| Watsonville to Smolyan | 6,614.13 mi (10,644.41 km) |
| Watsonville to Sofia | 6,513.61 mi (10,482.64 km) |
| Watsonville to Sopot | 6,549.20 mi (10,539.91 km) |
| Watsonville to Sozopol | 6,627.69 mi (10,666.24 km) |
| Watsonville to Sredets | 6,621.40 mi (10,656.11 km) |
| Watsonville to Stamboliyski | 6,576.28 mi (10,583.49 km) |
| Watsonville to Stara Zagora | 6,582.70 mi (10,593.84 km) |
| Watsonville to Svilengrad | 6,636.40 mi (10,680.26 km) |
| Watsonville to Svishtov | 6,502.46 mi (10,464.69 km) |
| Watsonville to Targovishte | 6,551.84 mi (10,544.17 km) |
| Watsonville to Teteven | 6,521.78 mi (10,495.80 km) |
| Watsonville to Troyan | 6,533.99 mi (10,515.45 km) |
| Watsonville to Tryavna | 6,552.40 mi (10,545.06 km) |
| Watsonville to Tutrakan | 6,502.39 mi (10,464.59 km) |
| Watsonville to Varna | 6,581.66 mi (10,592.16 km) |
