Accredited official statistics

Seafarers statistics: Background quality report

Published 22 February 2024

The purpose of this document is to provide users of the statistics with information about the quality of the outputs, measured against different dimensions of statistical quality.

As a result, this document helps to demonstrate how the Department complies with the Code of Practice for Statistics. These statistics are designated as Accredited Official Statistics. They undergo regular quality assurance to ensure they meet customer needs: Code of Practice.

Seafarers statistics are estimated by combining 2 data sources:

• an administrative data source on certificates from the Maritime and Coastguard Agency (MCA)
• a survey from members of the Chamber of Shipping (CoS)

The MCA data is sent to DfT annually who run initial validation checks. The data is checked for any missing or unusual data which is checked and verified by the MCA. The data is then combined with historical certificated data to produce initial trend analysis. Overall figures and breakdowns (such as age group and gender) are compared to the previous year to ensure the data is in line. This trend analysis is shared with MCA and any unusual or large year-on-year changes are checked and verified.

The CoS survey data is cleaned and validated by the CoS before being sent to DfT. DfT then combine the data with the historic CoS data and carry out initial trend analysis.  Overall figures and breakdowns (such as age group and gender) are compared to the previous year to ensure the data is in line. This trend analysis is shared with CoS and any unusual or large year-on-year changes are checked and verified.

For more background to these statistics, and information on how these statistics are produced please see the seafarers statistics technical note.

Section 1: Quality assessment

In this section, the quality of the statistics is considered in relation to the different dimensions of quality as stated in the European Statistical System (ESS) quality framework.

Relevance

Relevance is the degree to which a statistical product meets user needs in terms of content and coverage.

The statistical outputs presented within seafarer statistics include:

• a statistical release containing key findings, trends over time and signposts to further information

• Open Document Spreadsheet (ODS) data tables containing information on the number of seafarers by department, seafarer type, age, gender and nationality

• a technical note which provides background on the statistics, information about the different data sources, methodology information, and user feedback – see our guidance page

Known users and uses of the statistics

Within the DfT the statistics are used:

• for ministerial briefing and to answer public enquiries

• as background to policy development, for example understanding diversity in the maritime sector

• for monitoring trends in seafarer employment and activity

• by analysts for ad-hoc work for example assessing changes in demographics of seafarers

Outside of DfT, known users include:

• maritime organisations and employment unions to monitor seafarer activity

• other more general users who want to gain an overview of seafaring in the UK

How well the statistics meet user needs

In 2016, a seafarer user engagement exercise was published, seeking views on the use of the statistics and potential improvement. Although only 3 responses were received, together with a subsequent review of the statistics, the following areas were identified as being of interest:

User requests	DfT response
Improvements to the methodology used to compile estimates of seafarers active at sea   (although no specifics on how this should be done)	We collected data on seafarers active at sea working   for companies outside the membership of the UK Chamber of Shipping. Unfortunately, this data proved to be insufficient to allow improved estimates to be published at this time. Instead, we have tried to more clearly set out the coverage and limitations of the existing estimates, and present additional information alongside to give wider context. In 2020, we included proposals to estimate for non-respondents in the Chamber of Shipping (CoS) survey to ensure the results better represent the Chamber membership. We have been monitoring feedback on the proposed approach.
Information on trainee ratings to be included, where available	We have included further statistics on maritime apprenticeships in section 4 of the release.
Statistics relating to seafarers of other nationalities working in the UK industry	We have included published data tables including figures for non-UK seafarers from the EEA and the rest of the world, based on the Chamber of Shipping seafarer employment survey, and nationality   breakdowns based on the Maritime and Coastguard Agency (MCA) certification data.
Statistics on seafarer pay and conditions	This is not something that we are currently able to provide information on.

Accuracy and reliability

Accuracy refers to how close the estimated value in the output is to the true result.

These statistics aim to provide the best available estimate for the number of UK seafarers active at sea. Overall, the statistics are likely to provide a good indication of trends over time – however given the statistics provide an estimation the absolute numbers provided should be treated as an estimate. This is noted in the commentary of the release as appropriate.

The MCA data source on certificated officers comes from an administrative database, and data on certificated officers is comprehensive and of a high quality as officers have to hold certificates issued or recognised by the MCA in order to work in the profession.

However, when considering how accurately the figures represent estimates of UK seafarers active at sea there are some potential risks of error:

Certificates are valid for 5 years and the MCA does not hold information regarding the current employment status of certificated officers making it necessary to estimate the number of these officers who are active at sea. DfT mitigates this by assuming 16% of certificated seafarers are not active at sea. This is based on a 2004 study by London Metropolitan University (United Kingdom Seafarers Analysis 2004, D Glen, J Dowden and R Wilson, London Metropolitan University).

Changes to the certification system could impact figures. The department works closely with the MCA to understand changes to the MCA certification system and provide appropriate information in the statistical release if necessary (such as when new certificates are introduced).

In 2023, Small Vessel (SV) Engine certificates replaced Yacht and TIC Engine certificates. For 2023 onwards, legacy Yacht and TIC Engine certificates are included within SV Engine certificates in this release. SV Engine certificates cover those working on fishing vessels, yachts, tugs, workboats, standby, seismic survey, oceanographic research vessels and government patrol vessels. Therefore, SV Engine certificates are not comparable with TIC and Yacht Engine certificates in previous years.

The CoS survey provides estimates uncertificated officers and ratings, as well as certificated officer figures. There are a number of considerations that need to be taken into account when using the CoS survey data:

Although the survey is considered to be a reasonably comprehensive survey of the Chamber’s members with high response rates, they can vary across the years which can impact the overall trends and make it difficult to compare trends over time. In 2020, DfT included proposals to estimate for non-respondents in the CoS survey to ensure the results better represent the Chamber membership. We have been monitoring feedback on the proposed approach. Information on yearly response rates to the survey is included as background information in the release; these are monitored with the CoS to ensure the response rate remains high.

Not all seafarers in the UK shipping industry will be employed by CoS members, although the numbers employed elsewhere are expected to be small. DfT collected data on seafarers active at sea working for companies outside the membership of the UK CoS. Unfortunately, this data proved to be insufficient to allow improved estimates to be published. Instead, we have tried to more clearly set out the coverage and limitations of the existing estimates, and present additional information alongside to give wider context.

Some job titles provided by employers may be inconsistent, opening up the possibility of misclassification or inconsistencies over time. Before the survey is sent to DfT, the Chamber reviews the returns to ensure appropriate classification.

Combining all these points, the CoS statistics can fluctuate from year to year and should be treated with caution. Therefore, the results should be used as a general indication to broad levels of employment. This is indicated in the release where appropriate alongside the key findings.

Timeliness and punctuality

Timeliness describes the time between the data of publication and the date to which the data refers, and punctuality describes the time between the actual publication and the planned publication of a statistic.

Seafarer statistics are currently published annually, and provide figures as at June of the previous year. The MCA data is collected from an administrative database and is requested in September. The CoS survey is run in the summer months with cleaned and validated data provided in December. The production of the annual release usually begins in December once the CoS survey results have been collected and finalised. In most recent years the annual statistics have been published in February with data for the previous year (for example, 2022 statistics were published in February 2023).

Accessibility and clarity

Accessibility is the ease with which users are able to access the data, also reflecting the format in which the data are available and the availability of supporting information. Clarity refers to the quality and sufficiency of the metadata, illustrations and accompanying advice.

Accessibility

The outputs are published on the GOV.UK DfT statistics page in accessible formats:

• statistical releases are available as HTML reports
• data tables are available in ODS file format which can be accessed by using freely available software

Clarity

The statistical releases use plain language, in which technical terms, acronyms and definitions are defined where appropriate. The main findings are presented using a series of text and charts. Full details of the strengths and weaknesses of the data, as well as full definitions and a glossary, are provided in the seafarers technical note.

Coherence and comparability

Comparability is the degree to which data can be compared over time and domain. Coherence is the degree to which data that are derived from different sources or methods, but refer to the same topic, are similar.

Comparability

The statistical series for MCA certification data covers trends since 1997 for overall certificate trends, with further certificate breakdowns available from 2009. This data source is considered to be comparable over time until 2022, being extracted from the same administrative system. For 2023 onwards, data provided by MCA has been calculated using a different methodology and is not comparable with previous years.

The statistical series for the CoS seafarer employment survey covers trends since 2002 for uncertificated officers and ratings, and since 2010 for certificated officers. Fluctuations in trends over time for this data source should be interpreted with caution because:

• trends over time can be impacted by which companies respond in a given year

• trends over time can be impacted by companies joining and leaving the Chamber

In 2020, DfT included proposals to estimate for non-respondents in the CoS survey to ensure the results better represent the Chamber membership. When trends are impacted by companies leaving the Chamber, DfT includes this information in the release.

Coherence

There are limited sources available to make comparisons, however certificated data is available in both the CoS survey and MCA data. UK certificated officer trends across both data sources show a relatively stable trend over the last 10 years, although UK CoS certificated figures are lower than MCA data given the figures are only for Chamber members whereas the MCA figures relate to all UK seafarers with certificates.

The statistical release does not attempt to count everyone who works in a seagoing capacity in the UK. The focus is on the ‘merchant navy’ for which seafarer certification is managed by the MCA. The following are other groups that are outside the scope of this publication but may be considered to be in seafarer roles:

• the Royal Navy, which has a regular trained strength of around 38,000 based on Ministry of Defence statistics

• superyachts – most UK nationals working as crew aboard yachts will not be in scope of the above statistics (though Officers with MCA certificates to work on yachts will be included)

• inland waterways – MCA has issued 3,600 Boatmaster licences for work on inland waters and near coastal work over the 5 years to mid-2017

• those working in roles on shore

It is possible that seafarers can belong to more than one of these groups. Producing an overall estimate of all UK nationals working at sea from the available data is challenging.

Trade-offs between output quality components

Trade-offs between output quality components describes the extent to which different aspects of quality are balanced against each other.

The main trade off in these statistics is between timeliness and quality – the annual figures could be produced around a month earlier if a lower response rate was accepted for the CoS survey. Currently the annual release is published once the Chamber confirm that all possible responses for that year have been provided. Given the seafarers publication is assessed to be timely (usually published in February with data for the previous year) this approach is to maximise quality for the survey data.

Assessment of user needs and perceptions

Assessment of user needs and perception covers the processes for finding out about users and uses, and their views on the statistical product.

DfT regularly engages with users by social media, email and face to face methods when possible. This includes requesting regular feedback on the statistical series, with contact details provided in every statistical release. Each publication is promoted via Twitter.

DfT also regularly analyses web page usage, ad-hoc requests and social media analytics to monitor activity over time. In line with the Code of Practice for Statistics, users will be informed about any changes or revisions to the data series.

In 2016, a seafarer user engagement exercise was published, seeking views on the use of the statistics and potential improvement. Although only three responses were received, the feedback and subsequent actions were published in the technical note and are contained in section 1 of this report.

Performance, cost and respondent burden

Performance, cost and respondent burden describes the effectiveness, efficiency and economy of the statistical output.

The overall respondent burden related to these statistics is considered to be small.

The MCA data on certificates is sourced from an administrative database which records the information for operational purposes already, so the only additional burden for the MCA relates to compiling the figures and sending them to DfT, and working with DfT if there are any validation queries.

Depending on the size of the Chamber of Shipping and the response rate DfT can receive between 70 and 130 responses to the survey each year. It is considered that in most cases the employment figures can be easily extracted by CoS members from administrative or management information systems, as this information is likely to be recorded already for other purposes. Again, the only additional burden should be compiling the figures and sending them to DfT. Based on the length of the form and amount of information requested, it is expected that the survey should not take longer than 1 hour to complete.

Confidentiality, transparency and security

Confidentiality, transparency and security refers to the procedures and policy used to ensure sound confidentiality, security and transparent practices.

All data is stored, accessed and analysed using DfT secure IT systems. Data protection regulations are adhered to throughout the seafarer statistics production process, and any information provided to DfT by the MCA or the CoS is kept securely where access to data is controlled in accordance with departmental policy.

The information used to compile these statistics provides details on company name, seafarer age, gender and nationality. Some demographic details are provided at an individual seafarer level but no personal details are attached to these demographics. The published statistics do not include figures by individual company, as data is presented in an aggregated format. No statistical disclosure control methods are applied to the outputs, as variables included in the statistics are not considered to be sensitive.

DfT aims to publish as much data as is possible whilst ensuring that personal and commercial confidentiality is maintained.

DfT adheres to the principles and protocols laid out in the Code of Practice for Statistics and complies with pre-release access agreements. The pre-release access lists are available on the DfT website.

Section 2: Summary

This background quality report presents information for users of the seafarer statistics covering different aspects of quality. The department concludes, on the basis of the assessment outlined above, that the statistics are of a quality which is considered fit for the purposes for which the statistics are being used.

Comments and feedback on this report, or any other aspect of these statistics are welcome, and can be provided by email to seafarer statistics.

Further information

Data tables

Alongside each publication a series of data tables are published.

Technical note

The maritime statistics guidance page includes a technical note for the seafarer statistics. This contains notes and definitions, information about the data sources used, and strengths and weaknesses of the data.

Statistical quality

The European Statistical System (ESS) handbook for quality report provides comprehensive guidance on measuring the quality of statistical processes.

The Code of Practice for Statistics sets out common standards that should be followed by all UK organisations that produce official Code of Practice statistics.

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