From April 2023, it is a requirement in collision cases that even where only one party has the information in its possession, electronic track data (“ETD”) must be provided to the other party. This is a welcome amendment to the previous rule that the parties had to do so only where they both had ETD in their possession.

What is the Purpose of the Amendments?

The amendments to Part 1 and Part 2 of the Collision Statements of Case (“CSoC”) have been drafted with the aim of enhancing the ability of the parties and the Court to identify the substantive issues in dispute and manage the case more efficiently.

Whilst a CSoC is still pleaded “blind” i.e., without sight of the other party’s case, these amendments align CSoCs more closely with statements of case usually seen in the Commercial Court. However, it is clear from the minutes approving the amendments from the Civil Procedure Rule Committee meeting on 4 November 2022, that the amendments have deliberately retained the quirk of blind pleading, which has been a part of the Admiralty Court since the 19th century. Nevertheless, the amendments represent an acknowledgement of the changes needed given the advances of the 21st century.

Today, we no longer find ourselves having to draw plots on charts to determine how vessels collided or caused damage through negligent navigation. Advances in technology and particularly the use of Voyage Data Recorders (“VDR”) and Electronic Chart Display and Information Systems (“ECDIS”) allow for detailed and accurate reconstructions which show a clear picture of the vessels’ navigation. This enables the Court to focus on determining the “why” instead of the “how”.

The question, however, is what must a party to a collision case disclose and when?

ETD Disclosure Requirements

CPR 61(1)(m) defines ETD as (our emphasis in bold):

“A digital or electronic recording of the track of a vessel (including any associated visual or aural recordings) as recorded by, for example, ship or shore-based AIS (Automatic Identification System), ECDIS (Electronic Chart and Display Information System), or a voyage data recorder.”

PART 61 – ADMIRALTY CLAIMS – Civil Procedure Rules

It is often assumed that VDR data should be disclosed after the Acknowledgement of Service has been served in accordance with CPR 61.4 i.e., the CPR provision relating to ETD. However, this is not actually the case in CPR 61(1)(m). The CPR gives various examples of the type of recordings that could be ETD – a VDR being just one example. It is therefore arguable that the requirements of CPR 61 can be met by disclosing only the data from the ECDIS if a party is in possession of a separate recording that has been taken directly from the ECDIS rather than from the VDR. So long as that party complies with CPR Practice Direction 31B – requiring the recipient to have the same ability to access, search, review and display the information as the party providing it – there is little room to argue a failure in respect of the requirements relating to provision of ETD.  

[Dis]advantages of Disclosure?

CPR 61(1)(m) says that associated visual or aural recordings should be disclosed with the ETD. If a party is disclosing ECDIS data, then there will be no associated aural recordings. In contrast, if the ETD requirements are met by provision of VDR data, there will likely be associated aural recordings. This audio can and often does take a considerable length of time to review. Therefore, if a party can disclose ETD in the form of ECDIS data only, that party will have some space to listen to the VDR audio and prepare a transcript. VDR audio often provides compelling evidence relevant to the issues likely to be in dispute, i.e., the navigation of vessels in collision cases. It can make or break your case. Having to disclose what could potentially be adverse evidence at an early stage of the proceedings can have a significant impact on early attempts to reach a settlement. Therefore, if a party is able to meet its ETD obligation by providing ECDIS data, and thereby give itself more time to properly review its VDR audio, why would that party not do so?

Whilst Part 1 of the CSoC has been expanded to include a question as to the existence of bridge audio, the amendments have not gone so far as to say the bridge audio must be disclosed prior to CSoCs being served. This would suggest that disclosure of the audio is by no means a requirement at the early ETD disclosure stage. Given the potential importance of audio to the proceedings the question arises whether the Civil Procedure Rule Committee have gone far enough with these updates. Should they, for example, have introduced a requirement to disclose VDR audio (if available) at an earlier stage? It remains to be seen if further amendments will be made in the future.


Although the recent amendments have gone some way to improve transparency between parties by putting an end to the requirement for mutual, and only mutual, exchange of ETD, it is arguable they have not gone far enough. On the current CPR definition of ETD, there remains scope for a party to a collision case to withhold VDR audio where ECDIS data can be provided instead. This may give that party an advantage over a party who only has ETD in the form of VDR data or may take a more prescriptive approach to CPR 61(1)(m).

To avoid this, it remains open to any party to instruct its expert or attending solicitor to ensure that multiple forms of ETD are collected where possible. Being able to disclose only ECDIS data would enable a party in such a position to withhold VDR audio from the earlier stages of the proceedings. In turn, that party will have the opportunity fully to analyse its VDR audio and prepare a more accurate transcript. Given the likely significance of VDR audio to the outcome of the dispute, this extra time would allow a party in possession of such data to identify relevant strengths or weaknesses in its case and strategise accordingly.

At the early stages of a collision case, it is always better to be the party choosing which card to play, rather than being forced to reveal a potentially losing hand.