CDeception and spoofing can materially affect a vessel’s navigation and decision-making. These same issues may lead to disputes between landlords and tenants, as decisions taken in response to the intervention affect the performance of charterparty obligations.
In one case where HFW was directed by the Owners, the Master exercised reasonable judgment in determining that sailing was not safe, contrary to the charterers’ orders, due to interference and spoofing. The owner will likely confirm that this constitutes a reasonable deviation. Conversely, the charterer may assert that the vessel was not chartered because the vessel was not performing the requested service promptly. Whether the tenant’s argument is successful or not depends on the precise wording of the lease provisions at the charter party as well as the precise circumstances of the case.
However, it is possible that the charterer may be able to argue that under clause 15 of the standard NYPE the vessel was off charter for any time lost due to equipment failure. While there are no case authorities dealing directly with GPS jamming or AIS spoofing, in London Arbitration No. 23/89 the ship was unable to return to anchorage due to the condition of its radar and loss of time, with the ship deemed unchartered due to equipment failure.
In theory, a charterer could argue that a vessel unable to sail due to GPS or AIS issues is also uncharterable.
The crucial question is whether GPS interference counts as a malfunction. In Afrapearl (2004) 2 Lloyd’s Rep. 305 (CA), the court considered whether a leaking pipe qualified as equipment failure, holding that “…equipment failure such as a vacuum tube occurs when it no longer functions as a pipe.” Afrapearl also refers to The Thanasis A, unreported, of 22 March 1982, in which the judge commented in that decision: “…the cause of the breakdown is immaterial. It could be an external factor, or it could be some internal defect in the machinery or equipment, but if the machinery or equipment is not working, and perhaps also if it breaks down, then there is a failure in the machinery or equipment.”
Although based on the fact that the GPS is jammed so that the ship’s position is not shown at all, this is likely a malfunction. If GPS is spoofed, it is possible that the GPS receiver is not broken because it is still receiving and displaying GPS signals; It’s simply that these GPS signals are wrong. However, if the deceptive location is clearly false (such as showing the ship to be on land), the charterer’s argument that the GPS is faulty will be more convincing. Additionally, if the landlord has anti-jamming and anti-spoofing technology on board, and that fails, the renter could argue that the failure is related to the anti-jamming device, not the GPS system itself.
The owner may also assert that responsibility for the safety of the ship and crew, as well as navigational matters, ultimately remains with the owner.
However, no-hire clauses are usually drafted as no-fault clauses, meaning that the tenant only needs to prove that the circumstances fall within the suspension of hire clause.
Furthermore, because GPS and AIS should not be relied upon for visual and radar observations, owners also risk potential criticism for any delay if alternative navigation options are available. In London Arbitration Case No. 16/22, the ship experienced a power outage and was unable to follow the charterer’s orders for safety reasons. The court held that the ship had been off charter since the time of the power outage on board. Therefore, a court is unlikely to relieve the owner of liability when essential sources of navigation remain available.
Insecure port
Disagreements may also arise over whether a port is safe due to interference or spoofing occurring in the port, particularly in circumstances such as the temporary suspension of ship navigation ordered by Qatar in October 2025 in response to GPS-related disturbances (although the same issues may arise in any port affected by GPS interference).
In Leeds Shipping v Société Française Bunge (1958) 2 Lloyd’s Rep. 127, the Court held that “a port will not be safe unless, in the relevant period of time, a particular vessel can reach, use and return from it without running into danger which cannot be avoided by good navigation and seamanship, in the absence of some abnormal event.”
The first question is likely to be whether GPS interference is an “abnormal event.” In K/S Penta Shipping A/S v. Ethiopian Shipping Lines Corporation (1992) 2 Lloyd’s Rep. 545, where a ship was attacked by rebels after having previously visited the port more than 20 times, he considered that the attack was an abnormal event and that the port was not unsafe. When a port is known to be experiencing GPS interference, the issues will likely not be considered abnormal.
Another question is whether the danger can be avoided using good seamanship.
In circumstances where only the GPS is experiencing problems, with radar and all other navigational aids still operational in port, it is likely that any danger can be avoided by practicing good seamanship. Furthermore, as emphasized in Kodros Shipping Corp of Monrovia v Empresa Cubana de Fletes (1983) 1 AC 736, the concept of safety is not absolute, and where the charterer gives adequate warning of any GPS issues, the port will likely not be considered unsafe.
Seaworthiness
The classic test for seaworthiness was established in C. Bradley & Sons v. Federal Steam Navigation (1926) 24 Ll.L.Rep. 446: “A ship must have the degree of fitness which an ordinary prudent owner would require his ship to have at the commencement of her voyage having regard to all possible circumstances.” More specifically, The Aquacharm (1982) 1 Lloyd’s Rep 7 states that “the ship, crew and equipment shall be in all respects sound and able to meet and withstand the ordinary dangers of the sea during the contemplated voyage”. It is possible for the charterer and/or shipping authority to argue that the vessel was unseaworthy as the owner was aware of issues with the vessel’s GPS (or potential voyage-dependent issues) and did not exercise due diligence to protect the vessel, perhaps via anti-jamming and/or anti-spoofing software.
The courts have held on several occasions that crew incompetence can render a ship unseaworthy.
These occasions include inefficiency when calculating the amount of bunkers required (Macedonia (1962) 1 Lloyd’s Rep 316), incompetent attempts at firefighting due to unfamiliarity with the ship’s firefighting system and inadequate training in the safe transport of vehicles (Eurasian Dream (2002) 1 Lloyd’s Rep 719).
The claimant is also likely to rely on a wide range of international conventions and regulations governing standards of navigation and seamanship. For example, the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers states: “When acting on watch, the lifeguard officer shall ascertain the estimated or actual position of the vessel and confirm her course, course and intended speed, and shall note any hazards to navigation which he expects to encounter while on watch.”
If the crew is overly reliant on GPS or AIS, and is unable to determine the true position of the vessel using other methods (i.e. manual fixes on known objects or the use of ECDIS and radar overlays to highlight discrepancies when the ground is visible either via radar or from the bridge window), a court may find the vessel unseaworthy to transit an area that has been known for incidents of jamming or spoofing, due to crew incompetence.
Conversely, if the displacement is less obvious, for example displacing the vessel by only 50 meters while placing it in a shallow area, the court may be less inclined to make a finding of incompetence. In the event of a vessel running aground as a result of jamming or spoofing, charterers (and/or shipping interests) may seek to defend any averaging claim arising from the incident (or indeed make a claim for any losses suffered) by claiming that the vessel was unseaworthy. The evidence provided by the officer who was on watch and the steps taken to ascertain the true location of the vessel were likely to be pivotal.
The success of the tenant’s arguments in relation to the above areas of dispute will depend on the precise wording of the lease and the specific circumstances of each case.
Source: HFW, Baltic Stock Exchange
