The calculated distance (air line) between Hato Mayor del Rey and Boca Chica is approximately 31 miles respectively 50 kilometers.
By car or train, the actual journey to Boca Chica is certainly longer, as only the direct route (as the crow flies) between Hato Mayor del Rey and Boca Chica has been calculated here.
Air line (approximately)
50 kilometers
27 nautical miles