Coordinating Working Party on Fishery Statistics (CWP)

Fishery fleet

The term fishery fleet or fishery vessel refers to mobile floating platforms of any kind and size, operating in fresh, brackish or marine waters which are used for catching, harvesting, searching, transporting, landing, preserving and/or processing fish, shellfish and other aquatic organisms, residues and plants.

The term fishing vessel is used instead when the vessel is engaged only in catching operations.

The term non-fishing vessel applies to vessels performing other functions related to fisheries, such as supplying, protecting, rendering assistance or conducting research or training.

Fishery vessels are classified in accordance with the International Standard Statistical Classification of Fishery Vessels by Vessel Types (ISSCFV, 2019) (FAO, 2021a) which includes vessels engaged only in catching operations (i.e. fishing vessels) and other vessels supporting fishing related activities (i.e. non-fishing vessels such as motherships, fish carriers and reefers).

In order to assess fleet capacity, it is necessary as a bare minimum to have estimates of vessel numbers and main vessel characteristics. If the fleet consists of only one type of vessel, the number of fishing vessels may be used to express the total fishing power or capacity of the fishing fleet. If the fleet consists of vessels of different types, any survey to determine the capacity of a given fishing vessel would need to collect information on a number of vessel characteristics, including vessel type, gross tonnage, length and engine power. The exact fishing capacity indicator used will depend on the characteristics of the fishery or fleet and the availability of reliable data. For example, it is generally accepted that for trawlers the single most important factor is engine power. For gillnetters, however, engine power would be of limited importance. Applying a universal capacity measure across a range of fisheries may therefore prove inadequate in addressing the issue of global fishing capacity measurement.

Vessel tonnage

In international law, as well as in practice, two measurements of tonnage of ships have existed side by side: Gross Registered Tonnage (GRT) defined by the Oslo Convention (1947), and Gross Tonnage (GT) defined by the London Convention (1969). Although the London Convention has been adopted for vessels of 24 m in length and over, for many vessels only data by the Oslo Convention are available. The two measurements produce very different tonnage values, and the situation may vary from country to country, as measuring units defined at national level can also be used to determine the tonnage of vessels operating without an international tonnage certificate.

The magnitude of the task of reaching international agreement on standardized measurement units for vessel tonnage, of introducing these units into national regulations, and of re-measuring all fishing vessels is a lengthy, complex and costly process.

Vessel length

The most frequently used and preferred measure of the length of a fishing vessel is length overall (LOA) which refers to the maximum length of a vessel from the two points on the hull most distant from each other, measured perpendicular to the waterline.

Other measures of the length of vessels are:

  • Waterline length (LWL) which refers to the length of the designed waterline of the vessel. This measure is used in determining certain properties of a vessel for example, the water displacement;
  • Length between perpendiculars (LBP) which refers to the length of a vessel along the waterline from the forward surface of the stem, or main bow perpendicular member, to the after surface of the sternpost, or main stern perpendicular member. This measurement provides a proxy for the vessel's carrying capacity, as it excludes the small, often unusable volume contained in the vessel's overhanging ends. On some types of vessels this is, for all practical purposes, a waterline measurement. In a vessel with raked stern, this length changes as the draught of the ship changes, therefore it is measured from the defined loaded condition.

Vessel classification

For statistical purposes three main classifications were adopted by the CWP for classifying fishery vessels by tonnage, type and length:

  1. The International Standard Statistical Classification of Fishery Vessels by GRT Categories (FAO, 2021b), based on the Gross Registered Tonnage of the vessels.
  2. The International Standard Statistical Classification of Fishery Vessels by Vessel Types (FAO, 2021a), based on vessel types.
  3. The International Standard Statistical Classification of Vessels by Length Classes (FAO, 2021c), based on vessels' length overall.

Data collection

Data on fishery fleet are collected by means of the statistical questionnaire FISHSTAT FF. Form FF1 is used for the collection of data on decked vessels, whereas form FF2 is intended for undecked vessels for which the most important distinction is made between powered and not-powered crafts. For both FF1 and FF2 detail is requested about whether the vessels are operating in marine or inland waters. Numbers and power and tonnage (capacity data) are collected for broad groups of fishing vessel types based on the Simplified Classification of Fishing Vessels by Vessel Types (FAO, 2021d) and length overall has been defined as the main characteristic of measurement in international data collation (refer FAO, 2021c).


FAO. 1998. Fishery fleet statistics, 1970, 1975, 1980, 1985, 1989-95. Bulletin of Fishery Statistics No. 35. Rome, FAO. 501 pp.

Resources for fishery fleet

FAO. Fishing vessel type (fact sheets). [Cited 1 November 2020].

FAO. 2021a. International Standard Statistical Classification of Fishery Vessels by Vessel Types (ISSCFV, Rev.1, 2019). (also available at

FAO. 2021b. International Standard Statistical Classification of Fishery Vessels by GRT Categories (ISSCFV – GRT category) (ISSCFV, Rev.1, 1990). (also available at

FAO. 2021c. International Standard Statistical Classification of Vessels by Length Classes (ISSCFV – Length Classes) (ISSCFV, 1982). (also available at

FAO. 2021d. Simplified Classification of Fishing Vessels by Vessel Types. (also available at