When a ship is chartered on a time or voyage basis, it remains under the operational and legal control of the shipowner, who is responsible for the crew, maintenance, and operation of the vessel. Consequently, any harm caused by the ship may be attributed to the shipowner, as well as to the ship itself.

In addition, voyage charters and time charters may include provisions in which the charterer agrees to warrant the safety of ports and indemnify the shipowner against the risks of any breaches of the permitted trade clauses. When a ship is chartered out as a bareboat charter, the shipowner must be concerned about liability.

Shipowners typically warrant the seaworthiness of their vessels. Every charter agreement is deemed to include a generally recognized implied warranty of seaworthiness, even if the seaworthiness clause is not expressly stated in the charter party. Seaworthiness means that the ship is reasonably capable of safely transporting the cargo it has undertaken to transport within the specified trading areas, under the conditions that can reasonably be expected.

In cases of time or voyage charter, the shipowner or bareboat charterer typically retains control of the vessel, with the charterer merely providing commercial direction. The ship will operate within the parameters of the charter, loading and discharging cargo as required.

Traditionally, voyage or time charterers do not have authority over crew members and thus cannot be held accountable for their actions. However, if the charterer assumes responsibility for cargo-related operations such as loading, stowage, or discharging, then the shipowner may be held liable if any damage or loss occurs.

Bunker costs, including fuel for the main engine and auxiliary engines, can be a significant expense and are an important consideration in charter agreements. Under a bareboat charter, the shipowner assumes no responsibility for bunker costs as all operating responsibilities are assigned to the bareboat charterer. In a time charter, the time charterer is generally responsible for bunker costs incurred. In voyage charters, responsibility for bunker costs may be allocated to either party, depending on their preferences. Charterers must also allocate responsibility for bunkers that do not meet quality standards. Substandard bunkers may damage engines, cause power loss, and result in salvage costs, delays, or even the loss of the vessel. Failure to comply with regulations, such as sulfur content requirements, can result in civil penalties or detention.