Maritime Terms, Abbreviations and Acronyms

Maritime abbreviations and acronyms go back to those days we used telegram and telex to communicate. The business model for telex and telegrams was “pay per letter”. Even though the telegrams and telexes have been retired, we still use the maritime abbreviations daily.

Below you will find a comprehensive list of terms, abbreviations, and acronyms used in the maritime industry, sorted in alphabetical order. You can search for an acronym or write a word and find the abbreviations where the word is included.

If you think some abbreviations are missing, send us an e-mail at post@maritimeoptima.com or open the chat icon on the bottom of this page.

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ICS

International Chamber of Shipping

ICS

Institute of Chartered Shipbrokers

ICW

In connection with

ID

Import duty or Inside diameter

IDL

International Date Line

IE

Stands for “Immediate Exit.” In the U.S., Customs IE Form is used when goods are brought into the U.S. and are to be immediately re–exported without being transported within the U.S.

IFF

Institute of Freight Forwarders

IFO

Intermediate fuel oil

IG

Inert Gas

IGC

International Code for the Construction and Equipment of Ships Carrying Liquified Gases in Bulk (IMO)

IGM

Import general manifest

Ignition source

Includes heat, sparks, flames, static electricity and friction. Ignition sources should always be eliminated.

IGS

Inert Gas System

IGS

Inert gas system. If tankships let air fill their tanks as they pump out oil, an explosive mixture of hydrocarbon vapor and oxygen can form. Any spark, such as static electricity, could cause catastrophe. To eliminate this danger, modern vessels vent their tanks with gas which will not support combustion. Some use oxygen-depleted exhaust from the ship's engines. The most sophisticated systems fill empty space in tanks with nitrogen.

IHP

Indicated Horse Power

ILA

International Longshoremen's Association

ILG

Industry Lifeboat Group

Illuminating kerosene

see BURNING KEROSENE

ILO

International Labour Organization

ILOHC

In Lieu of Hold Cleaning

ILOW

In Lieu of Weighing

iMAS

integrated Marine Assurance System - BP's vetting system.

IMB

International Maritime Bureau

IMCO

Intergovernmental Maritime Consultitive Organisation

IMDG

International Maritime Dangerous Goods (Code)