the tug undertake to provide a towing service themselves, during which they are the performer, the crew, and supply, at the same time. Therefore, they undertake to provide 1) an agreed or specified service, or 2) to achieve an agreed specific result, or 3) to provide services for an agreed or specified period of time in exchange for periodic or lump sum payments.The keywords: contract of towage at sea, types of towing, contract of towage as a service contract, the responsibility of the tug owner, the responsibility of the owner of the towed vessel, towing and salvage.