Enforcing Your Patent Rights at Sea: A UK Perspective

Offshore Enforcement Boundaries: UK patent rights generally only cover the UK’s land and territorial waters, with some limited exceptions extending to the UK’s Exclusive Economic Zone.

A Considered Patent Strategy is Critical: Developing a patent portfolio that will capture acts that take place on land provides for the most effective strategy.

Identifying Key Markets is an Important Factor: For products that will eventually be put into effect at sea, obtaining patent protection in countries where the products are manufactured, and at key ports where they are likely to be placed onto ships, provides a mechanism to capture infringement on land.

Abstract

Companies focused on innovation for deployment at sea face additional considerations when looking to obtain patents on their inventions. From ships to oil rigs, and wind farms to underwater cables, patent strategies must consider whether the patents capture infringing acts and can be effectively enforced. This article will examine the impact of legislation including the Continental Shelf Act 1964 and the Petroleum Act 1998 on patent protection and enforcement in the UK, highlighting how these interact with the Patents Act 1977 to shape the enforceability of patent rights offshore. The article will also consider exceptions to patentability that may apply within UK waters. It will provide practical guidance on navigating the legislative considerations, and best practice for developing and implementing patent strategies tailored to inventions for deployment at sea, to ensure that innovators obtain enforceable rights.

Introduction

Grant of a patent provides you with a geographically restricted right to preclude others from infringing your patent, so an important aspect of any patent strategy is identifying the countries in which protection is desirable. However, in certain industries, including oil & gas, shipping, and sustainable fuels, activity often happens offshore. Therefore, where third parties are likely to undertake specific acts is particularly important, to ensure your patents capture infringement at locations where your patent can be enforced.

Territorial Extent of a UK Patent

A UK patent, whether obtained via a direct UK patent application, the validation of a granted EP patent in the UK,[1] or via the PCT procedure,[2] has effect in the UK mainland (England, Wales, Scotland, and Northern Ireland), the Isle of Man, and the territorial waters of the UK.[3] The territorial waters of the UK extend outward to a boundary reaching 12 nautical miles (22 kilometres) from the coastline.[4] Therefore, patentees can enforce their patents against any infringing acts taking place within these regions.

The UK Patents Act sets out a specific set of acts which constitute infringement:

• Where the invention is a product, making, disposing of, offering to dispose of, using, or importing the product, or keeping the product, whether for disposal or otherwise;
• Where the invention is a process, using or offering to use processes in the UK, where the person knows, or it is obvious to a reasonable person in the circumstances, that the use without consent would be an infringement;
• Where the invention is a process, disposing of, offering to dispose of, using, or importing products obtaining directly by means of the process, or keeping any product, whether for disposal or otherwise.

Therefore, any party performing any of these acts within the territory dictated for patent protection will be infringing, and the holder of the patent rights will be eligible for remedies from the courts if they successfully demonstrate infringement of their patent rights.

However, many sea-based commercial installations in the UK are outside the territorial waters of the UK, but within the UK’s Exclusive Economic Zone (EEZ). For companies innovating in mineral exploration and exploitation, section 132(4) of the UK Patents Act extends the territorial extent of patent rights to the areas defined in the Continental Shelf Act 1964 and the Petroleum Act 1998 for particular activities relating to mineral exploitation and exploration beyond the UK’s territorial waters and to the majority of the UK’s EEZ. The waters which to these Acts apply are defined by The Continental Shelf (Designation of Areas) Order 2013.

Within these waters, patent rights extend to the seabed and subsoil and their natural resources (except in relation to coal[5]) and in respect of any installation which is or has been maintained, or is intended to be established, for the carrying on of any of the following:[6]

1. activities connected with the exploration of, or the exploitation of the natural resources of, the shore or bed of the particular waters;
2. the exploitation or exploration of mineral resources in or under the shore or bed of waters;
3. the exploration of any place in, under or over such waters with a view to the storage of gas in such a place;
4. the conversion of any place in, under or over the particular waters for the purpose of storing gas;
5. the storage of gas under or over the particular waters or the recovery of gas so stored;
6. the unloading of gas at any place in, under or over the particular waters;
7. the conveyance of things by means of a pipe, or system of pipes, constructed or placed on, in or under the shore or bed of the particular waters; and
8. the provision of accommodation for persons who work on or from an installation which is or has been maintained, or is intended to be established, for the carrying out one of the above.

Limit of Territorial Extent and Exemptions

Notably, outside these activities, the territorial extent of a UK patent ends 12 nautical miles from the coastline, i.e. at the boundary of the territorial waters of the UK. Thus, companies innovating in sea-based wind turbine installations, which commonly fall outside the UK’s territorial waters and within the UK’s EEZ, shipping, or fishing will find that UK patent rights do not extend to locations where third parties may be performing infringing acts.[7]

There are also exemptions to patent infringement that apply to the vast majority of ships passing through UK waters. Under the UK Patents Act, where an infringing act consists of the use, exclusively for the needs of a relevant ship, of a product or process in the body of such a ship or in its machinery, tackle, apparatus or other accessories, the act does not constitute an infringement where the ship has temporarily or accidentally entered the internal or territorial waters of the United Kingdom.[8]

This exemption only applies to ships that are registered outside of the UK, in a country that is a member of the World Trade Organisation (WTO) or a party to the Paris Convention.[9] Prior litigation has confirmed that “temporarily” means that the provision applies irrespective of the frequency with which those ships enter UK waters.[10] Thus, so long as a ship is registered outside the UK, in a member country of the WTO or a signatory of the Paris Convention[11], it will fall within this exemption, and will not infringe.

As of September 2025, only 0.7% of the world's ships were registered in the UK,[12] so the vast majority of the world's ships will tend to fall under this exemption. Notably, however, ships registered to the Marshall Islands, a known flag of convenience having registered thereto 3.8% of the world’s ships (and a 12.5% share of the world total dead weight tonnage) do not fall within this exemption since the Marshall Islands is neither a signatory of the Paris Convention nor the WTO.

Best practices for sea-based innovation

For companies innovating outside of mineral exploration and exploitation, it can therefore be difficult to enforce UK patent rights at sea. However, with the right patent strategy, the prospects for capturing seabound infringement can be significantly improved.

The optimal strategy for capturing seabound infringement is to draft claims to target acts performed or apparatus used on land. In this way, the above limitations of a UK patent can be avoided, and more infringing acts may be captured. In this respect, it is important to draft patent claims to target acts which take place on land, before departure on a ship, to a wind farm installation, etc. For instance, for companies innovating in the renewable energy field, it is advantageous to try to protect parts of seabound installation that are produced on land, rather than only capturing products and processes that are installed/used in their final location at sea. For example, a claim to a specific wind turbine blade that is manufactured in the UK, or imported into the UK prior to installation, would be infringed on land. By contrast, there would only be direct infringement of a claim to a fully assembled wind turbine once it has been installed at sea. Similarly, a process by which the wind turbine acts when in use at sea would not be directly infringed within the territory of a UK patent.

Where patents protect sustainable maritime fuels, obtaining protection that covers key ports will be critical, because this will capture infringement where fuel is stored and where refueling takes place. Similarly, targeting protection in countries where competitors produce their fuels is typically advisable for a robust patent strategy.

However, patent strategies for other innovations relating to maritime fuels may be less straightforward. For instance, fuel additives may only be added to the fuel tank after a ship is outside the territorial scope of a patent. This reduces the value of patents protecting the use of the additive, and similarly impacts the enforceability of claims directed to combinations of additives that are only combined in the fuel tank. Where possible, obtaining protection for the additive as it would be sold by suppliers would be more valuable, because infringing acts like making, keeping and disposing of the product are likely to take place on land.

Additional considerations are needed for complex products made of a number of interacting parts, such as emission control systems designed to operate on ships. Where a product can be manufactured on site, obtaining protection for the individual parts results in rights that can be enforced at the point of manufacture or sale, rather than only upon final assembly on a ship.

Thus, for patents related to sea-based inventions, and in general, product/system claims that can be infringed on land, and method claims that take place on land, such as manufacturing, assembly, calibration, provisioning, loading, commissioning, remote monitoring/control, maintenance, should be prioritised.

For innovations in ships, ship machinery, etc., it may be more optimal to target filing patents where these ships or parts are manufactured and assembled to target infringement at the source. China, Japan, and South Korea currently account for over 94% of global shipbuilding capacity by gross tonnage.[13] Thus, protection in these countries is likely to provide significant commercial value for companies innovating in ships, and ship machinery (particularly for cargo ships), patent protection directed to the manufacture of the ships and ship machinery, as well as the manufactured product as such. In addition, European countries, such as Italy, France, Finland, Germany, United Kingdom, manufacture more specialised ships, such as icebreakers and cruise ships, so represent important countries within which to obtain patent protection in Europe.

Concluding remarks

Developing a considered patent strategy is critical to protect patent rights at sea. In the UK, innovators should focus on obtaining protection for products and processes that would be infringed on land, rather than final products that only exist at sea, and in shipping, targeting protection in countries where ships or their parts are made is critical. An enforceable patent strategy for sea-based innovation needs to be designed around where infringement can be proven and stopped.

Endnotes

[1] Section 77(1) UK Patents Act 1977 (UKPA 1977).

[2] Section 89(1) UKPA 1977.

[3] Sections 132(2) and 132(3) UKPA 1977.

[4] Section 1(a) Territorial Sea Act 1987.

[5] Section 1(1) Continental Shelf Act 1964

[6] Section 11(3) Petroleum Act 1998.

[7] Siemens v GE [2022] EWHC 3034 (Pat) has affirmed that the implications of the Continental Shelf Act 1964 and the Petroleum Act 1998 do not apply for wind turbine installations at sea.

[8] Section 60(5)(d) UKPA 1977

[9] Section 60(7) UKPA 1977

[10]  Stena Rederi AB v Irish Ferries Ltd [2003] EWCA Civ 66

[11] Paris Convention for the Protection of Industrial Property

[12] 2025 UN Review of maritime transport, Table II.2

[13] https://unctadstat.unctad.org/datacentre/dataviewer/US.ShipBuilding