HIGH SPEED CRAFT High speed craft operate connecting Colonia, Buenos Aires and Montevideo ports, crossing Martín García Channels in the vicinity of Km 58 and Km 60,1 and can change the routes in cases of bad weather. Mariners sailing along Canal del Norte and Quebrada del Banco Ortíz are advised to maintain a good lookout. Information concerning shipping movements can be obtained from Colonia Control Centre (CWC 23).