User guide – Water transport

User guide – Water transport

Notes and definitions

Change in the Department for Transport's method of compiling statistics of port traffic from 2000

A new data collection system for maritime traffic was introduced with effect from 2000. As a result, some data for 2000 onwards are not directly comparable with previous years. The reason for the change was to comply with a new EC Maritime Statistics Directive (Council Directive 95/64/EC on statistical returns in respect of the carriage of goods and passengers by sea).

One of the effects of this change is that some data for 2000, principally coastwise and one-port crude oil traffic, and the inland waters penetration of such traffic, are not directly comparable with information for previous years. However, the overall totals are unaffected.

Previously, all freight information was collected from ports annually. Major ports (generally those with cargo volumes of at least 2 million tonnes a year) were asked for detailed information on weight of traffic in and out of their ports, identifying cargo categories (eg liquid bulks, dry bulks, containers, Roll-on-Roll-off etc), and whether they were foreign, coastwise or one port cargoes. Other (minor) ports were required to provide only total weight of cargo inwards and outwards.

In the new collection system, most of the detailed freight information is collected from shipping lines, operators or shipping agents, which are required to supply detailed returns of their inwards and outwards traffic at each major port for each ship, on each route. Major ports (now defined as those with at least 1 million tonnes of cargo a year) are only required to supply summary information (for use as control totals) while other (minor) ports continue to provide just the total weight of cargo inwards and outwards.

One difference between the data from 2000 and previous years affects both coastwise and one-port crude oil estimates from 2000. The new collection arrangements produce much more reliable data on origins and destinations and (when aggregated) coastwise, one-port and foreign traffic summaries. Previously, this information was estimated by ports, with varying degrees of accuracy, particularly for crude oil traffic, which means that origins and destinations for crude oil data in 1999 and earlier years are approximate only, e.g. ports or refinery operators would not necessarily have been able to tell if crude oil was shipped directly from the UK offshore installation, or piped to a land terminal such as Sullom Voe and then shipped out from the land terminal, or if it was imported from a North Sea country or another foreign crude oil producer. As a consequence, it is likely that pre-2000, coastwise crude oil estimates were overestimated and one-port traffic correspondingly underestimated. This leads to the figures for coastwise traffic lifted in Scotland falling substantially in 2000 compared with 1999.

Ports which are part of selected major Scottish ports

a.) Clyde Port

b.) Forth

c.) Orkney


Port Locode


Port Locode


Port Locode













Port Glasgow








Hound Point














St Margarets Hope






Burray Pier












Flotta Terminal










Braefoot Bay


North Ronaldsay




Papa Westray








Scapa Flow


















Wemyss Bay








Lerwick is all ports on Shetland except for Scalloway and Sullom Voe, and Port Askaig is all ports on Islay.

Coastwise traffic

Traffic between ports of the United Kingdom, excluding traffic between a UK port and either the sea bed or an off-shore installation. It should be noted that Table 9.1(a) covers only freight lifted in Scotland, and therefore its figures for coastwise traffic exclude cargoes arriving from other UK ports; Table 9.1(b) covers freight discharged in Scotland, so includes cargoes arriving from other UK ports (including those elsewhere in Scotland).

One port traffic

Traffic between the sea bed or an offshore installation and a UK port. For example, it includes traffic to and from offshore installations, materials shipped for dumping at sea, and dredged sand and gravel etc landed at a port for commercial purposes. The disappearance of the sea dumped traffic is due to the end of sewage dumping at sea. It should be noted that Table 9.1(a) covers only freight lifted in Scotland: Table 9.1(b) contains figures for the one port traffic arriving from offshore installations and any incoming sea dredged aggregates. The reason for the increase in one-port oil traffic is due to increased number of crude oil shipments into Sullom Voe and Flotta, particularly from the newer Atlantic fields west of the Shetlands, Schiehallion and Foinaven.

Domestic traffic

In the statistics of traffic through the ports, domestic traffic comprises coastwise traffic plus one port traffic.

Foreign traffic

Traffic between ports in the United Kingdom and other countries.

Inland waterways

In general, waterways bounded by the furthest point downstream which is fewer than both 3 km wide at low tide and 5 km wide at high tide (spring). However, this definition is not applied strictly: for example, the definition is relaxed, where necessary, in order not to count, as inland waterway traffic, short-haul shipping movements of foreign and coastwise traffic, such as all sea-going traffic to or from major seaboard ports.

Inland waters traffic

Subdivides into coastwise, one port and foreign (in each case, that part of the traffic that is carried upstream of the inland waters boundary, excluding short haul inland movements of sea-going traffic) and internal (i.e. not sea-going) traffic. All passenger and passenger vehicle ferry services are excluded, such as crossing movements (e.g. Gourock-Dunoon) and coastwise ferries entering sheltered waters (e.g. Loch Ryan, on services between Stranraer or Cairnryan and Northern Ireland).


Where part of a voyage is on an inland waters and part is at sea, account is taken of the inland waterway boundary, so that, in the case of traffic involving inland ports, there is no double-counting of tonne-kilometres between the figures for inland waters and the figures for coastwise, one port and foreign traffic. (This is in contrast to the double-counting of some of the figures for tonnage - for example, if a voyage to another UK port starts on a Scottish inland waterway in Scotland, the tonnage would be counted in the figures for both inland waters and coastwise traffic.)

Container and roll-on traffic

Includes all traffic carried on special container and roll-on vessels, as well as the container traffic carried on conventional services.

Main Freight Units comprise containers, road goods vehicles, unaccompanied trailers, rail wagons, shipborne port to port trailers and shipborne barges only.

Ferry Routes within Scotland

The Scottish Government subsidises the principal operators of the Clyde and Hebrides ferry services (operated by CalMac Ferries Ltd), the Gourock – Dunoon passenger ferry service (operated by Argyll Ferries Ltd) and the Northern Isles (Orkney and Shetland) ferry services (operated by Serco NorthLink Ferries and Shetland Line 1984 Ltd). The companies providing most of the services, CalMac Ferries Ltd and Argyll Ferries Ltd, are part of the David MacBrayne Limited group. The following Local Authorities fund a number of ferry services: Orkney Islands Council, Shetland Islands Council, Highland Council and Argyll & Bute Council. Other services are privately operated.

Road Equivalent Tariff (RET)

The Road Equivalent Tariff (RET) scheme involves setting ferry fares on the basis of the cost of travelling an equivalent distance by road - Ministers have announced the Scottish Government's intention to:

  • continue RET as a permanent feature on the Western Isles, Coll and Tiree for passengers and cars, including small commercial vehicles and coaches
  • replace RET for larger commercial vehicles on the Western Isles, Coll and Tiree, with an enhanced pre-RET discount scheme
  • roll out a further RET pilot for passenger and cars including small commercial vehicles and coaches to Colonsay, Islay and Gigha from October 2012
  • roll out a further RET pilot for passenger and cars including small commercial vehicles and coaches to Arran from October 2014
  • roll out RET to other West Coast and Clyde islands within the term of this Parliament.

RET was introduced in the following routes in 2008: Oban-Castlebay-Lochboisdale; Oban-Coll/Tiree; Oban-Coll/Tiree/Castlebay; Uig-Tarbert-Lochmaddy; and Ullapool-Stornaway. RET was introduced to the following routes in 2012: Kennacraig-Islay, Kennacraig- Islay/Colonsay/Oban; Oban-Colonsay; and Tayinloan-Gigha.

Persons assisted

Coastguard statistics relating to persons given assistance do not include people who are rescued.


Most of this data is supplied by the Department for Transport (DfT). The Scottish Government obtains shipping service information from Caledonian MacBrayne, Western Ferries, Northlink Ferries, Orkney Ferries, Shetland Island Council and some of the other operators of shipping and ferry services.

Waterborne Freight Lifted in Scotland (Table 9.1)

Statistics of waterborne freight (coastwise traffic, one port traffic and inland waters traffic) are compiled by MDS-Transmodal Ltd under contract to the Department for Transport.

A number of data sources are used to determine the level of coastwise traffic, including the tonnage of goods reported in the port traffic statistics, (see below) and other surveys, and information about vessel movements. (The vessel movement data include the Northern Ireland, Orkney and Shetland ferry services, but exclude ferries operated by Caledonian MacBrayne and others in and around the Western Isles.) The pattern of coastwise shipping flows, by port and commodity group, is represented by origin and destination matrices, and combined with Admiralty information about the distances between ports. Where appropriate, account is taken of the inland waters boundary, so that there is no double-counting of tonne-kilometres between inland waters and coastwise shipping, in the case of traffic involving inland ports. The method which is used to derive the statistics of coastwise shipping involves some adjustments and reclassifications. As a result, the totals that it produces do not match the port traffic statistics for reasons which are described in the DfT Statistical Bulletin Waterborne Freight in the United Kingdom.

The principal sources for the statistics of one-port traffic are the port statistics (see section 9.16 below) and information about the distances between the ports and the at sea origins and destinations of the traffic, such as offshore installations and dumping grounds.

The sources of the inland waterway statistics are described below.

Traffic at Scottish Ports (Tables 9.2 to 9.9)

A new system for collecting detailed port traffic statistics was introduced in 2000 to comply with the requirements of an EC Maritime Statistics Directive. Annual traffic returns are made by shipping lines or their agents and port authorities. This information has been used to derive data on coastal and one-port traffic, and on the inland waters penetration of such traffic. From 1 January 2000, shipping lines or their agents are required to supply detailed statistics of foreign, coastwise and one-port traffic for all cargoes loaded or unloaded at major UK ports. Major ports are now defined as those ports with cargo volumes of at least one million tonnes in the previous year, plus a few smaller ports. The major ports handled 97 per cent of total port traffic in 2000. In addition, port authorities at the major ports are required to supply inwards and outwards control totals for each cargo category. For all other ports, the port authorities are required to supply just two figures: total inwards and total outwards traffic. The lack of detailed statistics for these minor ports means that a degree of approximation is required in the statistics for their traffic. For more details about the new data collection system, see DfT's publication 'Maritime Statistics'

For 1999 and earlier years, the port traffic statistics were produced, for the most part, from the records made by each port authority of the dues levied on goods passing through the port (supplemented, in some cases, by figures supplied by others).

From 1995 to 1999, the smaller ports (then defined as, generally, those with fewer than 2 million tonnes of traffic per year) were not required to supply detailed statistics - they provided only two figures, their inwards and outwards traffic. Full details of freight traffic were collected only for those ports with at least 2 million tonnes of cargo in the previous year (and for a few ports with less traffic): these were called the 'major' ports. In the 1995 and 1996 surveys, there were seven 'major' ports in Scotland: Aberdeen, Clyde, Cromarty Firth, Forth, Glensanda (on Loch Linnhe, south-west of Fort William, which exports crushed granite, which is classified in the statistics as crude minerals), Orkney, and Sullom Voe. In the 1997 and 1998 surveys, there were eight: these seven plus Cairnryan, which was counted as a major port because its 1996 return of its inwards and outwards totals had shown that its traffic exceeded 2 million tonnes in 1996. In 1999 the number of 'major' ports increased from eight to nine, since total traffic at Peterhead had exceeded 2 million tonnes in 1998. In 2000, with the introduction of the new definition of a major port (at least 1 million tonnes), Stranraer and Dundee became major ports, bringing the total in Scotland to 11.

Inland Waterways (Tables 9.10 and 9.11)

Statistics for internal traffic (ie traffic which is wholly within inland waters) are collected directly by DfT's contractor, MDS-Transmodal, from all known operators using personal interviews and postal questionnaires, supplemented by statistics from British Waterways collected primarily for toll levying purposes. Some information is also drawn from Maritime Statistics Directive returns where traffic is classified as internal movements and these traffic movements are then excluded from other traffic estimates to avoid duplication. For traffic moving to and from the open sea, the figures for inland waterway tonne-kilometres are calculated using information about the distances from each inland waterway boundary to the ports and wharves which are upstream of the boundary.

Shipping Services (Tables 9.12 to 9.17)

Transport Scotland obtains shipping service information from DfT (in respect of the services between Scotland and Northern Ireland, the Rosyth/Zeebrugge and Lerwick/Europe routes). Transport Scotland writes directly to Caledonian MacBrayne, Western Ferries, Northlink Ferries, Orkney Ferries, Shetland Island Council and the other major ferry operators in Scotland for the required information.

HM Coastguard Statistics (Table 9.18)

Statistics on search and rescue operations are obtained from the Maritime and Coastguard Agency.

Further information

Within Scottish Transport Statistics, further information can be found in:

  • Chapter 3 – Road freight,
  • Chapter 13 – International Comparisons (including water freight)

Other Transport Scotland Publications:

A relatively small number of ferry journeys compared to other modes means little data is available from the SHS.

The Department for Transport produces a number of related publications:

Transport Scotland:

Scottish Ferry Services: Ferries Plan (2013-2022)

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