A high-speed transportation system, the system comprising: at least one transportation tube having at least one track , the at least one transportation tube being at least partially arranged within a body of water ; at least one capsule configured for travel through the at least one transportation tube along a travel path between stations ; a propulsion system adapted to propel the at least one capsule through the at least one transportation tube ; and a levitation system adapted to levitate the capsule within the at least one transportation tube , wherein at least a portion of the travel path is arranged in the body of water under a surface of the water ; an underwater station ; a support structure arranged on or above the surface of the body of water and in electromechanical communication with the at least one tube , wherein the support structure comprises a docking platform floating on the surface of the water , the docking platform being structured and arranged for allowing a boat or other non-water transport vehicle to have access to the underwater station ; wherein an access channel connects the docking platform with the underwater station , wherein the access channel includes at least one elevator, wherein the underwater station is configured to receive cargo from the at least one elevator; wherein the system additionally comprises at least one active stabilizer comprising one or more motors for maintaining the at least one transportation tube at the predetermined depth (D) and/or orientation, characterized in that the support structure provides secondary floatation support for the at least one transportation tube . at least one transportation tube having at least one track , the at least one transportation tube being at least partially arranged within a body of water ; at least one capsule configured for travel through the at least one transportation tube along a travel path between stations ; a propulsion system adapted to propel the at least one capsule through the at least one transportation tube ; and a levitation system adapted to levitate the capsule within the at least one transportation tube , wherein at least a portion of the travel path is arranged in the body of water under a surface of the water ; an underwater station ; a support structure arranged on or above the surface of the body of water and in electromechanical communication with the at least one tube , wherein the support structure comprises a docking platform floating on the surface of the water , the docking platform being structured and arranged for allowing a boat or other non-water transport vehicle to have access to the underwater station ; wherein an access channel connects the docking platform with the underwater station , wherein the access channel includes at least one elevator, wherein the underwater station is configured to receive cargo from the at least one elevator; wherein the system additionally comprises at least one active stabilizer comprising one or more motors for maintaining the at least one transportation tube at the predetermined depth (D) and/or orientation, characterized in that the support structure provides secondary floatation support for the at least one transportation tube . <EOS>