I
IACS International Association of Classification Societies website
IADC   International Association of Drilling Contractors 
IAG International Association of Geodesy website 
IAGC  International Association of Geophysical Contractors 
IAGSA  International Airborne Geophysics Safety Association  website
IALA International Association of (Marine Aids to Navigation and) Lighthouse Authorities
IAPH  International Association of Ports and Harbours website 
IAS Instrument Air Supply
IBAMA   Instituto Brasileiro do Meio Ambiente (Brazilian environmental agency) 
IBC International Bathymetric Chart
  Intermediate Bulk Container 
IBCAO International Bathymetric Chart of the Arctic Ocean  website
IBCCA  International Bathymetric Chart of the Caribbean Sea and the Gulf of Mexico website
IBCEA  International Bathymetric Chart of the Central Eastern Atlantic website
IBCM   International Bathymetric Chart of the Mediterranean website 
IBCSEP  International Bathymetric Chart of the South Eastern Pacific 
IBCWIO International Bathymetric Chart of the Western Indian Ocean website 
IBCWP International Bathymetric Chart of the Western Pacific  
IC Institute of Corrosion website
  Incident Commander 
ICA International Cartographic Association  website 
ICAF  Implied Costs of Averting a Fatality
ICAO  International Civil Aviation Organisation website
ICAPS  Integrated Commissioning and Progress System
ICC  International Chamber of Commerce 
ICCP  Impressed Current Cathodic Protection
ICEA  Insulated Cable Engineers Association, Inc.(USA) website
ICES  International Council for the Exploration of the Sea 
ICLL  Intelligent Coordination and Logistics laboratory
ICM  Integrated Coastal Management 
ICMH  Inlet Cubic Meter per Hour
ICOE  International Council for Oil and the Environment 
ICON Intercalibration of Offshore NDT(multi-million pound European sponsored JIP)
ICONTEC Instituto Colombiano de Normas Tecnicas y Certificacion website
ICPC   International Cable Protection Committee 
ICRAM Istituto Centrale per la Ricerca Scientifica e Tecnologica Applicata al Mare website 
ICS Intervention Control System
  Incident Command System
  Integrated Compression System 
International Chamber of Shipping website 
ICSEM  International Commission for the Scientific Exploration of the Mediterranean webpage
ICSS  Integrated (or Information) Control and Safety System
  Instrumentation Control and Safety System 
ICT  Information & Communication Technologies 
  Implementation / Installation  Coordination Team
  Interface Control Technician 
  Interface Certification Test 
  Interface Coordination Team 
ID  Internal Diameter
IDB  Inter-American Development Bank  website
IDC  Intangible Drilling Costs 
  Inter Discipline Check
IDLH  Immediately Dangerous to Life and Health
IDSA International Diving Schools Association  website
IE Instrument Earth
IEA  International Energy Agency 
IEC  International Electrotechnical Commission website
IEEE Institute of Electrical and Electronics Engineers (USA) website 
IEI Internal External Insulation
IER Incremental Energy Rate
IERS International Earth Rotation and Reference System
IFD Issue For Design
IFO Intermediate Fuel Oil 
IFP Institut Francais du Petrole 
IFREMER  French Institute for Research into Exploitation of the Sea 
IFRS  International Financial Reporting Standard 
IG Inert Gas
IGBT  Insulated gate Bipolar Transistor 
IGC International Geological Congress  
IGCP International Geological Correlation Programme  webpage
IGIC Interim Gas Inventory Charge
IGOSS Integrated Global Ocean Services System (now subsumed within JCOMM)
IGS Inert gas System
  Inertial Guidance System
IGSC Interim Gas Supply Charge
IHO International Hydrographic Organisation 
IHR Incremental Heat Rate
IHUMS Integrated Health & Usage Monitoring System 
IIE  Institute of Industrial Engineers (USA) website
IIW  International Institute of Welding website
ILAH Interface Level Alarm High 
ILAL Interface Level Alarm Low
ILALL Interface Level Alarm Low Low
ILL International Leased Line (telecommunications)
ILO International Labour Organisation website
ILS Instrument Landing System
ILT  Industry Leadership Team 
IM Insulation Module 
Information Management 
IMA International Maritime Academy  website
IMCA  International Marine Contractor's Association
IMCO  International Maritime Consultative Organisation 
IMDG  International Maritime Dangerous Goods (Code of the IMO) webpage
IMMS  Integrated Marine Management System 
IMO  International Maritime Organisation   website  
IMP Integrity Management Plan 
IMPA  International Maritime Pilots' Association
IMR Inspection, Maintenance and Repair
IMS Internet Map Server (WCMC) website
IMT  Incident Management Team 
IMU  Incomer Management Unit
INCOSE  International Council on Systems Engineering
IND  Indicator of value 
INGAA Interstate Natural Gas Association of America
INLL  Interface Normal Liquid Level
INMARSAT International Maritime Satellite Organization website 
INS  Inertial Navigational System 
INTERTANKO International Association of Independent Tanker Owners
IOC International Oil Company
  Intergovernmental Oceanographic Commission  website   
IOCC Interstate Oil Compact Commission (USA)
IODE International Oceanographic Data Exchange website
IOMAC  Indian Ocean Marine Affairs Co-operation  website
IOOA   Irish Offshore Operators Association 
IOPC Fund International Oil Pollution Compensation Fund website
IOPCE International Oil Pollution Conference and Exhibition (Singapore 1999) 
IOPP  International Oil Pollution Prevention (certificate of) 
IOR Improved/Increased Oil Revovery
IOS Interconnected Operations Services
IOSC  International Oil Spill Conference website 
IOSH  Institution of Occupational Safety and Health (UK) 
IOU Investor-Owned Utility
IP Institute of Petroleum
  Identification of Position
  Image Processing 
  Immersible Pump  
  Implementation Procedure
  In Progress
  Instrument / Indicator Panel
  Individual Protection 
  Input 
  Inspection Plan / Procedure 
  Installation Plan 
  Integrated Plan / Process / Program 
  Intensive Production  
  International Protection (CENELEC)  
  Intersection Point 
  Initial Production
IPAA   Independent Petroleum Association of America 
IPE Instrument Protective Earth 
  I-Profile European (beam) 
  International Petroleum Exchange
IPIECA International Petroleum Industry Environmental Conservation Association. website
IPN  Metal beam type
IPS  Integrated Power Station 
IPPC Integrated Prevention Pollution Control
IPPS Instrumented Pressure Protection System
IQ Image Quality Indicator  
IQC  Incoming / Internal Quality Control 
IR Infra Red  
  Individual Risk 
IRCN  French Naval Construction Research Institute website 
IRGA Infra Red Gas Analyser
IRGD Infra Red Gas Dectector 
IR(&)M  Inspection Repair & Maintenance 
IRP Integrated Resource Planning
IRPA  Individual Risk Per Annum
IRT Integrated Remote Technology
IS  Irish Sea. 
Intrinsically Safe
ISA  Instrument Society of America (USA) website
ISDN  Integrated Services Digital Network (digital telephone line) 
ISE  Intrinsically Safe Earth
ISEA  Industrial Safety Equipment Association (USA) website 
ISF International Shipping Federation
ISGI International Service for Geomagnetic Indices website
ISGOTT  International Safety Guide for Oil Tankers & Terminals  webpage
ISI  InterSymbol Interference 
ISM   International Safety Management (IMO code for ships) webpage
ISMA   International Ship Managers Association 
ISO International Standard Organisation webpage
ISPS Integrated Secondary Power System
  Integrated Self Protection System
  INternational Ship & Port facilities Security 
ISPWP International Society for the Prevention of Water Pollution  webpage
ISRS International Society for Rocks Mechanics
  Inside Screw Riser Spindle
ISS  Iron and Steel Society (merged into AIST : website )
ISSMGE International Society for Soil Mechanics and Geotechnical Engineering 
ISSOW  Integrated Safe System Of Work 
ISU  Insulation/Integrated system unit
  International Salvage Union
IT  Integration Test
Information Technology
ITB  Invitation to Bid
ITC  Internal Tree Cap 
ITCP  Integrated Technical Co-operation Programme (IMO website
ITE  Information Technology Equipment
ITIL Information Technology Infrastructure Library webpage
ITOPF International Tanker Owners Pollution Federation Limited
ITP  Interface Test Program 
  Integrated / Inspection Test Plan 
  Individual Training Program 
  Integrated Transport Platform 
  Initial Trials Phase 
ITRF International Terrestrial Reference Frame 
ITT  Invitation To Tender
ITU  International Telecommunications Union
IUCN  International Union for the Conservation of Nature 
IUGG International Union of Geodesy and Geophysics  website 
IUGS International Union of Geological Sciences website  
IUGS/CGM IUGS Commission for Marine Geology  
IUGS/COGEODOC IUGS Commission on Geological Documentation 
IUGS/COGEODATA Commission on Storage, Automatic Processing and Retrieval of Geological Data 
IUGS/COMTEC Commission on Tectonics 
IW Injection Well
IWIS Intelligent Well Interface Standard 
IWOCS  Installation and Work Over Controls System 
IWS  In Water Survey