Harbour authorities across the UK are increasingly prosecuting boat users for breaching local byelaws. More individuals are receiving summonses to the Magistrates’ Court for offences such as speeding within a harbour’s jurisdiction or failing to follow local regulations.

Harbour authorities, ports and the Maritime Coastguard Agency (MCA) continue to emphasise to boat and watercraft users the importance of navigating waters safely.

The Port Marine Safety Code was updated in 2025 and sets out national standards for the management of marine facilities such as harbours, ports, marinas, and berths. The Code was published by the MCA and Department of Transport to provide a framework to put safety at the forefront of maritime operations and ensure the powers and responsibilities of different organisations are recognised. Amongst other things, the Code asks that marine facilities evidence compliance with these minimum standards and highlights that organisations must have the power to create byelaws and an appropriate enforcement policy in place.

This article explains the powers Harbour authorities hold, how investigations work and what to expect if you are invited to a voluntary interview or prosecuted for breaching a harbour byelaw.

The Power to Prosecute

Due to the large quantity of legislation and regulations relating to harbours, it is crucial to understand the scope of powers harbour authorities hold. Those powers are conferred by local Acts of Parliament or Orders. Accompanying this local legislation, the Harbours, Docks and Piers Clauses Act 1847 provides provisions for the making, improvement and regulation of harbours, docks and piers, permitting a harbour authority to make byelaws for certain purposes.

As many seafarers will know, harbours often have their own byelaws to regulate safe navigation within and around the harbour. It is important to know the limits of the harbour for the purposes of abiding by the byelaws. One common example is byelaws that impose a speed limit in specific areas of the harbour.

The byelaws are local laws and there is often a penalty for non-compliance, which can result in a trial at the Magistrates’ Court and a fine on conviction. Under criminal law, these cases are considered summary only offences (the least serious criminal offences in England and Wales) and tried exclusively in the Magistrates’ Court.

Voluntary Interviews

Those involved, or suspected of being involved, in an incident likely to be considered an offence contrary to a byelaw or other local regulation may be invited to a voluntary interview under caution. An interview under caution is an opportunity for suspects to inform authorities of what happened and allows someone to put their version of events on record for the purposes of an investigation.

These interviews are conducted in accordance with the Police and Criminal Evidence Act (PACE) 1984 and Codes of Practice so the prosecuting authority can rely on the evidence provided in the interview if a prosecution is pursued. For the offence of breaching a byelaw, individuals are not under arrest and so may leave at will. There is also a right to information according to PACE Code C so an interviewee (or their solicitor) can understand the nature of the offence and why they may be suspected of committing it. This right to information is limited though and those investigating the incident do not have to disclose all the information.

A caution is given at these interviews as this is required before a person is charged or informed they may be prosecuted. The caution is as follows: “You do not have to say anything. But it may harm your defence if you do not mention when questioned something which you later rely on in Court. Anything you do say may be given in evidence.”

During the interview, an individual may reply ‘no comment’ or remain silent. However, there is no restriction on the court drawing an adverse inference from such silence. Pursuant to the Criminal Justice and Public Order Act 1994, if one fails to mention facts when questioned that they later rely on as a defence in court (or would reasonably be expected to have mentioned it in interview), the court may draw an adverse inference.

Crucially, everyone has a right to legal advice before an interview under caution and attendance is voluntary. Usually, there are four options should one attend an interview under caution: (i) answer all questions; (ii) give a ‘no comment’ interview; (iii) provide answers to some questions but not others; or (iv) provide a handwritten statement and provide a ‘no comment’ interview.

Evidence and Procedure

The Magistrates’ Court has its own rules on procedures. For summary offences, including the breach of a byelaw, there is a time limit of 6 months from the incident for the prosecuting authorities to ‘lay’ their case before the Magistrates’ Court.

An individual accused of an offence will then be sent a summons, which directs the accused to appear at court to plead guilty or not guilty for the offence(s) alleged at a hearing. The Magistrates’ Court (Amendment) Rules 2019, introduced changes with regards to what is required to be included in a summons and made serving (formally delivering) the summons easier by permitting service via email in some cases.

Pursuant to the Criminal procedure Rules 2025, the accused can request details of the prosecution’s case, which will include witness statements or any account given by the accused in interview.

The prosecution may also reach out to the accused to request whether they object to witnesses giving evidence in written form at trial. Under section 9 of the Criminal Justice Act 1967, if the correct procedure is followed and a defendant does not object, a witness can provide a written statement instead of attending court.

Sentencing

A summary only offence for the breach of a byelaw often leads to a fine on conviction. Prosecuting authorities have various powers and it is important to understand this when determining the height of a fine that can be imposed on conviction.

If one pleads guilty, a Magistrates’ Court will likely proceed to sentencing at the first hearing date. There is a reduction in sentence for a guilty plea and the court considers when the indication to plead guilty was made. The Sentencing Council guidelines indicate that where an individual pleads guilty plea at the first stage of proceedings, a reduction of one-third should be made. However, the level of reduction in sentence for pleading guilty is at the discretion of the court and reduces the closer to the trial one gets.

Avoiding a Summons

Navigating without knowledge of local regulations can lead to serious consequences. It is important to be familiar with local byelaws to conduct yourself safely, comply with local laws and avoid prosecution for non-compliance.

Individuals should use local authority websites to review regulations and stay up to date with local mariner guides, which are posted on harbour authority websites. If in doubt, reach out to the harbour master’s office for clarity and request a copy of the local byelaws.

Legal advice should be obtained to ensure individuals understand the legal implications and consequences of a prosecution by the harbour authority. LA Marine has extensive experience in regulatory and investigative matters.

To speak to a member of the LA Marine team, please email online.enquiries@LA-law.com.