As part of the Structures des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiment, four Mediterranean water eddies (Meddies) were identified in the Canary Basin and tracked with freely drifting RAFOS floats. One large and energetic Meddy, discovered 1700 km west of Cape Saint Vincent, Portugal, set a distance and speed record as it translated another 1700 km southwestward at 3.9 cm/s during 1.5 years. This Meddy traveled 57% of the distance from Cape Saint Vincent toward the spot McDowell and Rossby <1978> found a possible Meddy north of the Dominican Republic. Two Meddies were observed to interact with the Azores Current as they passed underneath or through it. Three Meddies collided with tall seamounts, which seemed to disrupt the normal swirl velocity, perhaps fatally in two cases. One Meddy appeared to bifurcate when it collided with seamounts. ¿ 1998 American Geophysical Union