The British Admiralty Court’s jurisdiction and its ship arrest powers are what make it one of the world’s leading forums for maritime disputes. Sitting within the King’s Bench Division of the High Court, the court hears a defined list of shipping claims under Section 20 of the Senior Courts Act 1981, including collisions, cargo loss, salvage, crew wages, and mortgage disputes.1Legislation.gov.uk. Senior Courts Act 1981 – Section 20 Its distinctive feature is the ability to arrest a vessel as security for a claim, holding it in port under a warrant executed by the Admiralty Marshal until the shipowner puts up acceptable security or the ship is sold.
What the Court Has Authority Over
Section 20 of the Senior Courts Act 1981 sets the outer limits of the court’s reach. The list is broad, covering almost every dispute that can arise from operating a ship.1Legislation.gov.uk. Senior Courts Act 1981 – Section 20 The main categories are:
- Damage done by a ship and damage received by a ship, from open-water collisions to port infrastructure struck during berthing.
- Ownership and possession disputes, including disagreements between co-owners about how a vessel is used or its earnings divided.
- Loss of life or personal injury caused by defects in a ship or its equipment, or by the negligence of the owner, charterer, master, or crew.
- Loss of or damage to cargo carried in a ship, and disputes over carriage or charter agreements.
- Salvage, towage, and pilotage of ships or aircraft.
- Goods, materials, dock charges, and construction or repair work supplied to a vessel.
- Master’s and crew’s wages.
- Mortgages and charges on a ship.
Crucially for cross-border shipping, this jurisdiction is not limited to British-flagged vessels. Claims involving foreign ships routinely come before the court, which is a large part of why London remains a global centre for maritime litigation.1Legislation.gov.uk. Senior Courts Act 1981 – Section 20
In Rem Versus In Personam
Admiralty claims divide into two very different actions, and the choice shapes everything that follows.
An action in rem is brought against the ship itself. The vessel is treated as the defendant, which is what allows a claimant to establish jurisdiction by seizing the ship even when the owner is based overseas and has no other assets in England and Wales. Section 21 of the Senior Courts Act 1981 governs when this is available. For claims about ownership, mortgages, or forfeiture, the action lies against the specific ship connected to the dispute. For most other Section 20 claims, it lies against the ship involved provided that the person who would be personally liable was the owner, charterer, or person in control at the time the cause of action arose, and remains the beneficial owner of all shares in the ship when the action is filed.2Legislation.gov.uk. Senior Courts Act 1981 – Section 21
Where a maritime lien exists, the claim attaches directly to the vessel and survives a change of ownership. A new buyer inherits the lien whether they knew about it or not.
An action in personam is a conventional lawsuit against a named person or company. It works like any other High Court claim and does not require the vessel to be within the jurisdiction. The trade-off is straightforward: without the ship as security, enforcing a judgment against a foreign entity with no English assets can be very hard.
Sister Ship Arrest
One of the more powerful features of proceeding in rem is sister ship arrest. If the person liable was the owner or charterer of the ship connected to the original dispute, a claimant can instead arrest a different ship, provided that same person beneficially owns all the shares in the substitute vessel when the action is brought.2Legislation.gov.uk. Senior Courts Act 1981 – Section 21
There is a firm limitation. Once any ship has been served or arrested to enforce a particular claim, no other ship can be served or arrested in that or any other action in rem for the same claim.2Legislation.gov.uk. Senior Courts Act 1981 – Section 21 You get one shot. Picking the right vessel is a commercial decision as much as a legal one.
How a Ship Arrest Works
Arresting a ship is what gives admiralty claims their commercial weight. A vessel sitting under arrest in port is a strong incentive for a shipowner to negotiate or post security, because every idle day costs money. The procedure sits in Part 61 of the Civil Procedure Rules.3Justice UK. Civil Procedure Rules – Part 61 – Admiralty Claims
Documents and Undertaking
A claimant or judgment creditor seeking arrest files a claim form together with an application for a warrant of arrest on Form ADM4 (application and undertaking for arrest and custody) and Form ADM5 (declaration in support).4GOV.UK. Admiralty Forms Before the warrant issues, the claimant must request a search of the Register to check whether a caution against arrest is in force for the vessel.3Justice UK. Civil Procedure Rules – Part 61 – Admiralty Claims
The application must include an undertaking by the claimant’s solicitor to pay the Admiralty Marshal’s reasonable costs of serving the warrant and keeping the ship in custody. Those costs include berthing charges, watchmen’s fees, and other expenses that build up for as long as the arrest lasts. They can ultimately be recovered as part of the claim, but the arresting party carries them in the meantime.
If the target vessel belongs to a foreign state, the claimant must first serve notice on the consular officer for that state in London or at the relevant port before the warrant can be issued.3Justice UK. Civil Procedure Rules – Part 61 – Admiralty Claims
Executing the Arrest
Only the Admiralty Marshal, or a substitute the Marshal appoints, can carry out the arrest. Once the warrant is executed, the ship enters custodia legis: custody of the law. It cannot be moved without a court order, and the Marshal may immobilise it or otherwise prevent it from sailing as appropriate.3Justice UK. Civil Procedure Rules – Part 61 – Admiralty Claims A warrant of arrest is valid for 12 months, but it can only be executed if the claim form has been served or is still valid for service at the date of execution.
Getting the Ship Released
An arrested ship is released once the parties agree security to cover the claim. In practice, that takes one of three forms: a cash deposit paid into court, a bank guarantee, or a letter of undertaking from the shipowner’s Protection and Indemnity (P&I) club. P&I letters are widely accepted in English practice, though a claimant is not obliged to accept one.
The amount should reflect a realistic assessment of the claim, not the claimant’s most optimistic figure. Once the security is in place, the claimant files a request for release with the Admiralty Marshal, together with a further undertaking to cover the Marshal’s costs of releasing the ship. An officer then removes the arrest papers and the vessel is free to sail.
Speed matters. Port charges, crew costs, and cargo delays accumulate every day the ship is detained, and experienced practitioners on both sides usually move quickly for that reason.
Wrongful Arrest Exposure
English admiralty law sets a high bar before a claimant is liable for wrongful arrest. Damages are awarded only where the arrest was carried out in bad faith or with gross negligence. Simply losing the underlying claim is not enough. The arresting party must have known the arrest was unjustified or acted with reckless disregard for whether a valid claim existed. This standard traces to the nineteenth-century decision in The Evangelismos, and it protects claimants who act in good faith on a genuinely arguable case.
The practical effect is that arrest carries relatively low risk for a claimant with a legitimate dispute. Unlike many other forms of interim relief in English civil procedure, the court does not require a cross-undertaking in damages as a condition of issuing an arrest warrant. Using arrest to apply commercial pressure without a genuine claim, however, is exactly the sort of conduct that can attract a damages award.
Priority When a Ship Is Sold
If the dispute cannot be resolved and no security is posted, the court can order the Admiralty Marshal to appraise and sell the vessel. The Marshal appoints valuers to certify the ship’s true value and then sells it for the highest price obtainable. It cannot be sold below the certified value without a further court order. Sale proceeds are paid into court, the sale is advertised, and other parties typically have 28 days from publication to file claims against the fund.5GOV.UK. ADM14 Order for Sale of a Ship A court-ordered sale is one of the few transactions that transfers a vessel free of all existing encumbrances, so the buyer takes clean title.
Proceeds are then distributed in a strict order:
- Admiralty Marshal’s costs of arrest, custody, and sale, paid first.
- Maritime liens, including salvage, crew wages, and damage done by the ship. These rank ahead of registered mortgages regardless of when the mortgage was recorded.
- In rem claims where the claim form was issued before the date of the mortgage.
- Registered mortgages, in the order they were registered.
- Unregistered mortgages.
- All other creditors.
The ranking protects those who saved the vessel or worked aboard it over commercial lenders. If proceeds are insufficient, lower-ranked claimants may recover a fraction of their claim or nothing at all. Anyone considering arrest as a route to recovery needs to understand where they will sit in this waterfall before spending money on the process.
When Arbitration Displaces the Court
Not every maritime dispute reaches the Admiralty Court. Most international shipping contracts contain arbitration clauses pointing to London arbitration under the rules of the London Maritime Arbitrators Association (LMAA), and London has been the dominant seat for maritime arbitration for decades.
Where a contract includes an arbitration clause, admiralty proceedings on the substantive dispute may be stayed in favour of arbitration. The court retains its arrest powers, however, which lets a claimant arrest a vessel to obtain security and then pursue the underlying claim in arbitration. That combination of court-ordered security and private resolution is a large part of why London holds the position it does in maritime dispute work.