Are most of the rivers in Spain and Mexico navigable?

Most rivers in Spain and Mexico are not navigable. Rivers in Spain that are navigable are along the Atlantic Ocean and the Mediterranean Sea. They include the Guadalquivir, Tagus, and Ebro rivers. Rivers in Mexico that are navigable are along the Gulf of Mexico and the Pacific Ocean. They include the Rio Grande, Coatzacoalcos, and Papaloapan rivers.