Glossary

Maritime glossary, terms beginning with X

All maritime glossary terms that begin with the letter X, drawn from every subject section. 261 entries.

Showing 250 of 261 terms (page 1 of 2).

X (Maritime Anonymisation) X143. Landmark Maritime Law Cases and Doctrines: Convention for anonymised parties in LMAA awards.
X Band Marine Radar X109. Maritime Autonomous Surface Ships and MASS Code: A short to medium range marine radar widely used on commercial and autonomous vessels for navigation and collision avoidance.
X Band SART X80. Maritime Search and Rescue Coordination: SART responding to 9 GHz radar pulses.
X DF X19. Engine Room Watchkeeping and UMS Operations: WinGD dual fuel two stroke engine family using low pressure Otto cycle.
X Performance Level X75. IMDG Code, Classes, Packing and Segregation: UN packaging marking indicating suitability for Packing Groups I, II and III.
X Pursuit Race F4. Recreational Boating, Yachting and Sport: Generic regatta format.
X Reduction Factor X112. IMO GHG Strategy, CII, EEXI and EU Maritime Regulation: Percentage cut from the EEDI Reference Line that defines the Required EEDI for each ship type and phase.
X Salvage Award X167. Major Salvage Companies, Wreck Removals, and Equipment: Generic placeholder for the LOF arbitrator's final monetary award.
X Topmark X23. AIS, GMDSS, IALA Buoyage and Aids to Navigation: Yellow St Andrew's cross identifying a special mark.
X type engine X19. Engine Room Watchkeeping and UMS Operations: Designation for WinGD low speed engines, examples X62, X72, X82, X92.
X-35 F4. Recreational Boating, Yachting and Sport: One-design performance cruiser.
X-99 F4. Recreational Boating, Yachting and Sport: One-design cruiser-racer designed by Niels Jeppesen.
X-band X23. AIS, GMDSS, IALA Buoyage and Aids to Navigation: 8 to 12 GHz radar band (9.2 to 9.5 GHz for marine radar and Racons).
X-band radar B3. Nautical Science: 9.4 GHz band marine radar.
X-band radar (ice) X27. Polar Code, Ice Navigation and Polar Operations: 9 GHz marine radar used for detecting growlers and small bergy bits.
X-band radar evidence X163. Marine Accident Investigation Agencies and Landmark Inquiries: Class of operational evidence (navigation radar imagery and recorded tracks) used by investigators to reconstruct collision and grounding sequences.
X-band Radar Standards X158. IMO Conventions, Protocols, Codes, and Resolutions: Radar performance standards under Resolution MSC.192(79) made mandatory through SOLAS V/19.
X-Band Radar Tracking X22. Piracy, Maritime Security and Armed Protection: Use of high resolution radar to detect small skiffs at extended range.
X-band radar training X21. STCW Certificates, Crewing and Seafarer Welfare: Equipment specific awareness within Radar Observer and Radar Navigation courses.
X-Band Radar Wave Imaging X129. Hydrographic Offices, Survey Vessels and Marine Cartography: Use of marine X-band radar returns to estimate sea state and surface currents, complementing hydrographic surveys.
X-Band Wave Radar X96. Hull Integrity Monitoring and Strain Gauges: Marine radar operating in the 9 GHz region used as the basis for systems such as WaMoS and Furuno WR-2120.
X-Bitt X173. Mooring, Anchoring, OCIMF MEG4, and Equipment Numeral: Cross or X-pattern bollard formed by intersecting bitts at right angles, providing several lead directions.
X-Body Carrier X169. Container Terminal Cranes, Yard Equipment, and Lashing: Specialty straddle carrier configuration with reinforced legs for heavy projects.
X-Bow X35. Yacht and Superyacht Industry: Inverted-bow architecture pioneered by Ulstein, used on REV Ocean and other explorers.
X-bow (Ulstein, propulsion impact) B2. Marine Engineering: Hull form impacting machinery slamming loads.
X-Bow (Ulstein) X27. Polar Code, Ice Navigation and Polar Operations: Inverted bow form used in offshore polar service vessels for sea-keeping rather than icebreaking.
X-bow flag State approval X7. Flag State, Port State Control and Detention Vocabulary: Flag-state acceptance of novel hull forms under SOLAS II-1 equivalence provisions.
X-Bow Hull X126. Marine Oil Spill Response and OPRC Regimes: Ulstein design used on Norwegian offshore response vessels.
X-Bow Influence X30. Tug Operations and Harbour Towage: Reference to inverted bow forms occasionally explored in tug research, distinct from production tug bows.
X-bow OSV (Ulstein) B5. Ship Types and Individual Vessels: OSV/PSV with X-bow hull form.
X-Bow Pilot Boat X159. Marine Pilotage, Pilot Districts, and Pilots' Associations: Ulstein-designed bow form used by several Northern European pilot boats to reduce slamming in heavy weather.
X-bow stern interaction X38. Propellers, Stern Gear and Shaft Lines: Effect of Ulstein X-Bow hull form on aft flow; relevant where propeller wake is influenced by altered hull pressure distribution.
X-Bow yacht X156. Superyacht Industry, Builders, and Yacht Charter Market: Inverted bow yacht design popularized on explorer yachts for improved seakeeping in head seas.
X-Cargo X1. Cargo Science, Commodities and Cargo Care: Category X NLS under MARPOL Annex II; most stringent discharge rules.
X-Category NLS (Annex II Reg 6) X171. MARPOL 73/78: Annex-by-Annex Detailed Glossary: A noxious liquid substance presenting a major hazard, requiring prewash under Reg 13.6 and discharge of resulting effluent to a reception facility before departure.
X-class X42. Offshore Wind Installation and Cable Lay: Cadeler vessel class encompassing Wind Orca and Wind Osprey.
X-Class operation X156. Superyacht Industry, Builders, and Yacht Charter Market: Informal designation for yachts authorized for unrestricted commercial trading under the REG Large Yacht Code.
X-class pilot license X32. Marine Pilotage and Pilot Operations: Authority-specific top tier endorsement for largest vessels, terminology varies by jurisdiction.
X-clause incorporation X152. Maritime Arbitration and Dispute Resolution: Generic term for selective incorporation of charterparty clauses into bills of lading, with arbitration incorporation governed by cases like The Federal Bulker and The Channel Ranger.
X-Connect X122. Submarine Cable Laying, Repair Vessels and Operators: Generic cross-connect term used in cable landing stations between SLTE and terrestrial backhaul.
X-Craft F1. Maritime History: Royal Navy midget submarines of the Second World War.
X-Crew Welfare X154. Maritime Welfare, Seafarer Charities, and MLC Rights: Industry shorthand for welfare provision to former crew members no longer in service, covered by charities like Royal Alfred and Sailors' Children's Society.
X-DF (WinGD) B2. Marine Engineering: Otto-cycle dual-fuel two-stroke engine.
X-DF 2.0 X134. LNG and LPG Carrier Operators and Containment Systems: Second generation WinGD low pressure dual fuel engine with improved methane slip performance, deployed from 2022 newbuildings.
X-DF iCER X90. Marine Engine Specific Model Enumeration: WinGD X-DF generation featuring intelligent control by exhaust recycling to reduce methane slip and improve efficiency.
X-DF Otto Cycle D6. Decarbonization, emissions and alternative fuels: Two-stroke gas engine cycle used by WinGD.
X-DF Wartsila X174. Marine Engine Maintenance, Overhaul, and Condition Monitoring: Wartsila two-stroke dual-fuel low-pressure gas engine family including X62DF and X72DF for LNG-fuelled vessels.
X-DF-A X34. Decarbonization, Alternative Fuels and Carbon Pricing: Ammonia variant of WinGD's X-DF engine family.
X-DF-M X34. Decarbonization, Alternative Fuels and Carbon Pricing: Methanol variant of WinGD's X-DF engine family.
X-DF2.0 X90. Marine Engine Specific Model Enumeration: Second generation of WinGD low-speed two-stroke dual-fuel engines with iCER and improved emissions performance.
X-DF2.1 X90. Marine Engine Specific Model Enumeration: Refined iteration of the WinGD X-DF2 dual-fuel two-stroke generation.
X-flow Demister X69. EGCS Scrubbers, SCR and Marine Air Emissions: Cross-flow demister arrangement used in some compact scrubber towers.
X-Force Pipelay X37. Marine Spatial Planning, Subsea Cables and Submarine Pipelines: Internal project name occasionally used for high-capacity pipelay campaigns.
X-Lashing X9. Cargo Securing, Lashing and Stability Vocabulary: Crossed lashing pattern providing both transverse and longitudinal restraint.
X-Listed Cargo X135. Chemical Tanker Operators and IBC Code Cargoes: MARPOL Annex II Category X substance such as phenol or aniline solutions, the most stringently regulated cargo category requiring shore-discharged prewash.
X-Marker, IALA Special F5. The Reference Layer: Glossary, Units, Signals and Information Sources: Yellow X-topmark special mark.
X-Notation X8. IACS, Class Rules and Class Notations: society-specific marker, for example RINA's X prefix on optional descriptive notations.
X-Press Feeders X166. Inland Waterways, Ferries, RoRo, and Short Sea Shipping: The Singapore-headquartered global common-feeder container operator, the largest independent feeder operator outside Europe.
X-Press Feeders Agency X86. Port Agency, Husbandry and Disbursement: Agency support for X-Press Feeders, a major feeder operator.
X-Press Feeders Methanol Series X111. Methanol, Ammonia and Alternative Marine Fuels: Series of 1,170 TEU methanol dual-fuel feeder container ships operated by X-Press Feeders.
X-Press Iris X111. Methanol, Ammonia and Alternative Marine Fuels: 2023 delivery in the X-Press Feeders methanol dual-fuel feeder series.
X-Press Pearl X53. Marine Insurance, P&I and Hull Clauses: The container ship that caught fire and sank off Colombo, Sri Lanka in May and June 2021, generating one of the most significant container-related environmental incidents and large insurance and…
X-Press Pearl (2021) X12. Maritime Casualties and Investigation: Singapore-flag container ship that caught fire off Colombo on 20 May 2021 and sank on 2 June 2021, releasing billions of plastic pellets; investigated by Singapore TSIB and Sri Lanka.
X-Press Pearl Casualty (2021) E1. Maritime security, geopolitics and risk: High-profile fire/loss illustrating cargo and pollution security risk.
X-Press Pearl incident X18. Ballast Water, Biofouling and Antifouling: 2021 container ship fire off Sri Lanka; relevant to broader marine environmental risk literature but not BWM-specific.
X-Press tidal X57. Ocean Energy Beyond Wind: Generic placeholder for tidal stream developer trade names and prototypes.
X-ray Diffraction in Conservation F2. Maritime Culture, Heritage, Archaeology, Art and Museums: Analytical method used on Mary Rose finds.
X-Ray Diffraction in Hull Surveys F5. The Reference Layer: Glossary, Units, Signals and Information Sources: Materials-test method.
X-Ray Examination X29. Ship Sale and Purchase, Management Contracts and Valuation: Non-destructive testing of welds, sometimes required at delivery.
X-ray facility X36. Shipboard Medical, Telemedicine and Seafarer Health: Not standard aboard cargo ships; available on larger cruise ships' infirmaries.
X-ray fluorescence (XRF) X47. Marine Fuel Quality and ISO 8217: Spectroscopic technique used for sulfur and trace metal determination per ISO 8754, ISO 14596, and related methods.
X-ray Fluorescence (XRF) IHM Sampling X118. Ship Recycling Yards, Beaches and Regulation: Field XRF used during IHM sampling for screening of lead, mercury, and chromium in paints and coatings.
X-Ray Fluorescence Analyzer X50. Ship Recycling, Demolition and Hong Kong Convention: A field analytical instrument used by IHM experts for rapid identification of lead, cadmium, and chromium in coatings and metals.
X-Ray Fluorescence XRF Testing X28. Ship Recycling and End-of-Life: Field screening for heavy metals in paints and coatings during IHM sampling.
X-Ray Inspection X5. Marine Surveying and Inspection: Radiographic NDT method for weld root and internal defects.
X-Ray Inspection (Bonded Stores) X120. Marine Catering, Provisions and Ship Chandlers: Customs check used in some US and UK ports for sealed bonded lockers.
X-ray Inspection (CTU) X172. IMDG Code: Classes, Divisions, Segregation, and Key UN Numbers: A non-destructive screening method recommended in 7.8 for verifying segregation and load distribution in CTUs.
X-Ray Inspection Heavy Cargo X104. Project Cargo Forwarders and Heavy Transport: Non-destructive inspection of welds and lift points on project cargo.
X-ray radiography B4. Shipbuilding, Materials, Sea Trials, Retrofits and Recycling: Standard volumetric NDT method.
X-ray scanner X15. Ports, Terminals and Stevedoring: gate or non-intrusive inspection scanner, e.g., Smiths HCV-Mobile, Nuctech.
X-ray scanning C3. Logistics, freight forwarding and multimodal trade: Non-intrusive customs inspection.
X-ray screening X24. Cruise, Passenger Ship and Ferry Operations: Mandatory ISPS baggage screening at cruise terminal entry.
X-Reference Notation F5. The Reference Layer: Glossary, Units, Signals and Information Sources: Generic chart cross-reference symbol.
X-rudder X11. Naval Vessels, Warship Systems and Naval Architecture: Cruciform stern control surface in X orientation, used on Soryu and Type 212.
X-Series X90. Marine Engine Specific Model Enumeration: WinGD electronically controlled low-speed two-stroke smart engine family covering X35 through X92 platforms.
X-type rudder X162. Naval Architecture, Stability, Resistance, and Structural Design: Cruciform rudder arrangement, common in submarine practice.
X-Y Plotter D2. Hydrography, tides, waves, bathymetry and marine geology: Historical chart plotting device used in hydrography.
X-Yacht Owner's Association F4. Recreational Boating, Yachting and Sport: Class association.
X-Yachts F4. Recreational Boating, Yachting and Sport: Danish production performance cruiser brand.
X.509 X25. Maritime Cybersecurity, OT and IT: ITU-T standard for public key certificates used throughout TLS and code signing.
X.509 Certificate E3. Technology, digitalization and smart shipping: PKI certificate format used in eBL and SSAS.
X1 Wind X105. Offshore Wind Farm Installation and Vessels: Spanish floating wind developer behind the PivotBuoy tension leg downwind platform demonstrator.
X12 X6. Container, Intermodal and Trade Codes: ANSI ASC X12 EDI standard family used in North America.
X3 hydrogel X165. Marine Coatings, Antifouling, and Hull Husbandry: Hempel Hempasil X3 silicone-hydrogel fouling release chemistry combining low surface energy with bound water.
X35 X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke marine engine with 350 millimeter bore for handysize and small bulk carrier propulsion.
X35B X90. Marine Engine Specific Model Enumeration: Upgraded mark variant of the WinGD X35 low-speed two-stroke marine engine.
X40 X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke marine engine with 400 millimeter bore for handysize bulker and tanker propulsion.
X40DF X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke dual-fuel methane variant of the X40 platform.
X52 X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke marine engine with 520 millimeter bore for supramax and panamax tonnage.
X52DF X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke dual-fuel methane variant of the X52 platform.
X62 X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke marine engine with 620 millimeter bore for panamax and aframax tonnage.
X62B X90. Marine Engine Specific Model Enumeration: Upgraded mark variant of the WinGD X62 low-speed two-stroke marine engine.
X62DF X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke dual-fuel methane variant of the X62 platform.
X62DF-M X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke methanol dual-fuel variant of the X62 platform.
X72 X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke marine engine with 720 millimeter bore for aframax and post-panamax tonnage.
X72DF X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke dual-fuel methane variant of the X72 platform.
X72DF-A X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke ammonia dual-fuel variant of the X72 platform entering early commercial service.
X82 X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke marine engine with 820 millimeter bore.
X82B X90. Marine Engine Specific Model Enumeration: Upgraded mark variant of the WinGD X82 low-speed two-stroke marine engine.
X92 X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke marine engine with 920 millimeter bore used on very large container vessels.
X92B X90. Marine Engine Specific Model Enumeration: Upgraded mark variant of the WinGD X92 low-speed two-stroke marine engine.
X92DF X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke dual-fuel methane variant of the X92 platform used on large LNG dual-fuel container vessels.
X92DF-A X111. Methanol, Ammonia and Alternative Marine Fuels: WinGD two-stroke ammonia dual-fuel main engine in the 92 centimeter bore class for large container ships and tankers.
X92DF-A WinGD X140. Ammonia as Marine Fuel and Hydrogen Shipping: Marine engine model designation for ammonia-fueled VLACs.
X92DF-M X90. Marine Engine Specific Model Enumeration: WinGD low-speed two-stroke methanol dual-fuel variant of the X92 platform.
Xanadu X125. Superyacht Industry, Builders and Brokers: Common past name applied to several superyachts.
Xanten Roman Boats F2. Maritime Culture, Heritage, Archaeology, Art and Museums: First-century vessels excavated in Germany.
Xanten Roman River Boats F1. Maritime History: First-century inland vessels excavated in Germany.
Xanten University Limes Maritime Program F3. Seafaring Life, Education, Professions and Institutions: Roman-frontier maritime history teaching.
Xanthate Mineral Processing Records X50. Ship Recycling, Demolition and Hong Kong Convention: A representative downstream metals processing input.
Xanthates X1. Cargo Science, Commodities and Cargo Care: Mining reagents; some IMDG Class 4.2 self-heating.
Xanthid Bycatch D4. Fisheries, aquaculture, blue economy and marine resources: Bycatch of mud crabs in trap fisheries.
Xanthos Welfare Adjacency X154. Maritime Welfare, Seafarer Charities, and MLC Rights: Greek-tradition seafarer-pension and benevolent arrangements grouped under the broader Greek seafarer welfare system.
Xbloc X175. Port Engineering, Dredging, Breakwaters, and Quays: Single-layer concrete armour unit developed by Delta Marine Consultants of the Netherlands in 2003.
Xbloc Plus X175. Port Engineering, Dredging, Breakwaters, and Quays: Single-layer concrete armour unit developed by Delta Marine Consultants as an evolution of the Xbloc with smoother surfaces.
XBOX Reporting X127. Maritime Security, Anti-Piracy and PMSCs: Informal name for ReCAAP ISC's incident classification CAT-1 through CAT-4 (no formal XBOX code exists).
XBRL Tagging (Sanctions Disclosure) X151. Maritime Sanctions, Dark Fleet, and Price Cap Regimes: A reporting modality used by some EU member states for sanctions-related corporate disclosures.
XBT D1. Physical and chemical oceanography and marine meteorology: Expendable Bathythermograph used for routine upper-ocean temperature profiling.
XBT (Expendable Bathythermograph) X129. Hydrographic Offices, Survey Vessels and Marine Cartography: Single-use probe measuring temperature versus depth, sometimes used with a fixed salinity profile to estimate sound speed.
XBT (Expendable Bathythermograph) Data X150. Tanker Vetting: OCIMF SIRE, CDI, RightShip, and TMSA: Hydrographic data products that voyage planning checks may reference under SIRE 2.0 navigation chapters.
XBT Transect D5. Coastal processes, sea-level, cryosphere and ocean observation science: Repeated XBT profile lines collected from ships of opportunity.
Xcel Cable Crossing X37. Marine Spatial Planning, Subsea Cables and Submarine Pipelines: Reference to power cable crossing approvals in the US Midwest.
XChange (Marlink) X68. Maritime Satcom and Telecommunications: Marlink onboard service delivery platform.
XCMG X15. Ports, Terminals and Stevedoring: Chinese maker of reach stackers and forklifts used in some terminals.
XCMG XGC88000 X104. Project Cargo Forwarders and Heavy Transport: Chinese-built crawler crane in the 4,000 tonne class for refinery and nuclear work.
XCTD D1. Physical and chemical oceanography and marine meteorology: Expendable CTD providing salinity and temperature profiles.
XCU Cover X4. Marine Insurance, P&I and Claims: explosion, collapse and underground damage cover, occasionally relevant in marine construction.
XDR X48. Maritime Cybersecurity: Extended Detection and Response, an integrated approach combining endpoint, network, and cloud telemetry.
XDR Extended Detection and Response X25. Maritime Cybersecurity, OT and IT: Platform unifying EDR, NDR and SIEM telemetry.
Xebec F1. Maritime History: Three-masted Mediterranean vessel with lateen and square rig combinations.
Xebec Carving Tradition F2. Maritime Culture, Heritage, Archaeology, Art and Museums: Mediterranean ornamentation of historic vessels.
Xebec Heritage F2. Maritime Culture, Heritage, Archaeology, Art and Museums: Mediterranean lateen-rigged historical vessels.
Xebec-Frigate F1. Maritime History: Hybrid French Mediterranean cruiser type.
Xeneta Reefer X136. Reefer Vessels and Cool Chain Operators: Norwegian freight rate benchmarking service with reefer container rate index data.
Xeneta XSI C1. Commercial shipping, chartering, economics and finance: Container freight rate index based on shipper contract data.
Xenia Maritime Code F5. The Reference Layer: Glossary, Units, Signals and Information Sources: Generic example of regional maritime reference.
Xenoestrogen D3. Marine environmental science, pollution and conservation: Synthetic compound mimicking estrogen, environmental endocrine disruptor.
Xenon Bulb (Galley Hood Lighting) X120. Marine Catering, Provisions and Ship Chandlers: IMPA 791010 series replacement bulb, included in stores order.
Xenon Compressed X75. IMDG Code, Classes, Packing and Segregation: UN 2036, Class 2.2 non flammable non toxic gas.
Xenon Flashing Light F5. The Reference Layer: Glossary, Units, Signals and Information Sources: High-intensity navigation aid lamp.
Xenon Refrigerated Liquid X75. IMDG Code, Classes, Packing and Segregation: UN 2591, Class 2.2 cryogenic gas.
Xenon Sailing School F4. Recreational Boating, Yachting and Sport: Generic example of training school.
Xenon search light X35. Yacht and Superyacht Industry: High-intensity bridge-mounted searchlight used on superyachts for night navigation.
Xenon Strobe Light F5. The Reference Layer: Glossary, Units, Signals and Information Sources: High-intensity strobe used on liferaft locator lights.
Xenon Stroboscope X67. Marine Electrical Systems and Shore Power: Instrument used to time and balance rotating electrical machinery during commissioning.
Xenophon's Anabasis F2. Maritime Culture, Heritage, Archaeology, Art and Museums: Classical narrative including Black Sea coastal navigation.
Xenophyophore X10. Marine Biology, Fisheries and Oceanography: Giant single-celled foraminifer-like protist of the deep sea.
Xeresean Wine Crates F2. Maritime Culture, Heritage, Archaeology, Art and Museums: Sherry-trade ephemera preserved in port museums.
Xeresean Wine Trade F1. Maritime History: Sherry export trade from Cadiz and Jerez.
Xerion Shipping Academy F3. Seafaring Life, Education, Professions and Institutions: Generic example of private cadet training provider.
Xerox Chart Folio F5. The Reference Layer: Glossary, Units, Signals and Information Sources: Historic copy-based chart management.
Xerox of Continuous Discharge Certificate F3. Seafaring Life, Education, Professions and Institutions: Historical practice for seafarer record.
Xerox of Crew List F4. Recreational Boating, Yachting and Sport: Common notice-of-race requirement.
Xerxean Decree F2. Maritime Culture, Heritage, Archaeology, Art and Museums: Iconographic motif in Persian and Greek art of the maritime campaigns.
Xerxean Naval Defeat F1. Maritime History: Battle of Salamis, 480 BCE.
Xerxes' Bridge of Boats F1. Maritime History: 480 BCE Persian pontoon crossing of the Hellespont.
Xerxes' Hellespont Heritage F2. Maritime Culture, Heritage, Archaeology, Art and Museums: Preserved memory of the Persian crossing.
XGen Vessel D6. Decarbonization, emissions and alternative fuels: Generic term for next-generation low-emission vessel.
Xhibitionist X125. Superyacht Industry, Builders and Brokers: Speculative Gray Design concept yacht.
Xi Jiang X33. Inland Navigation and Barge Operations: West River, principal navigable branch of the Pearl River system in southern China.
XI-1 (Special Measures to Enhance Maritime Safety) X170. SOLAS 1974 Convention: Chapter-by-Chapter Glossary: Chapter added by 1994 SOLAS Conference, comprising regulations 1 through 7.
XI-2 (Special Measures to Enhance Maritime Security) X170. SOLAS 1974 Convention: Chapter-by-Chapter Glossary: Chapter added by 2002 SOLAS Conference, mandatory from 1 July 2004.
Xia class X11. Naval Vessels, Warship Systems and Naval Architecture: PLAN Type 092 first-generation SSBN.
Xiamen X124. Dredging Industry and Reclamation Contractors: Chinese port maintenance by CCCC fleet.
Xiamen International Boat Show F4. Recreational Boating, Yachting and Sport: Chinese marine industry event.
Xiamen Maritime Cluster F3. Seafaring Life, Education, Professions and Institutions: Chinese coastal maritime services hub.
Xiamen Maritime College F3. Seafaring Life, Education, Professions and Institutions: Chinese maritime training institution.
Xiamen Maritime Museum F2. Maritime Culture, Heritage, Archaeology, Art and Museums: Chinese coastal port museum.
Xiamen Pilots X159. Marine Pilotage, Pilot Districts, and Pilots' Associations: Xiamen Pilotage Station serving the south Fujian coast ports of Xiamen and Zhangzhou.
Xiamen Port Group X138. Global Container Terminal Operators and Port Equipment: SSE-listed parent operating Haitian, Yuanhai joint venture and Songyu terminals, 12.5 million TEU handled in 2023.
Xiamen Trade F1. Maritime History: Historic Amoy port commerce in tea and porcelain.
Xiamen University Maritime Affairs Program X121. Maritime Education, Academies and Universities: Marine policy and trade research center in Fujian.
Xiamen Yuanhai Container Terminal X138. Global Container Terminal Operators and Port Equipment: Hutchison Ports facility at Fujian Xiamen, capacity 1.6 million TEU.
Xian Cable Manufacturer Reference X37. Marine Spatial Planning, Subsea Cables and Submarine Pipelines: Chinese cable manufacturing facilities supplying domestic submarine power projects.
Xian Jiaotong University Marine Mechanical Engineering X121. Maritime Education, Academies and Universities: Inland Chinese marine mechanical research with Yangtze applications.
Xian Maritime Texts F2. Maritime Culture, Heritage, Archaeology, Art and Museums: Tang-period accounts of Indian Ocean trade.
Xian Y-8MPA X130. National Coast Guards and Cutter Fleets: China Coast Guard maritime patrol aircraft based on Antonov An-12, operating from Sanya.
Xiao Yang X124. Dredging Industry and Reclamation Contractors: CCCC small hopper.
Xijiang X166. Inland Waterways, Ferries, RoRo, and Short Sea Shipping: The "West River," the principal tributary of China's Pearl River, navigable from Wuzhou to Guangzhou for 1,000 t vessels and from Nanning seasonally.
Xikomba FPSO X153. Offshore Drilling Rigs, FPSOs, and Offshore Vessels: Saipem-built FPSO previously operating on the Xikomba field offshore Angola before redeployment.
Xin Hai Hu X124. Dredging Industry and Reclamation Contractors: CCCC TSHD.
Xinde Marine News F3. Seafaring Life, Education, Professions and Institutions: Chinese maritime industry media.
Xinhua Bunker X116. Global Bunker Anchorages, Hubs and Supply Infrastructure: Reference name occasionally used for Sinopec subsidiary bunker tanker operations in Zhoushan.
Xinhua Maritime Coverage F3. Seafaring Life, Education, Professions and Institutions: Chinese state media's maritime reporting.
Xinhui Plant X83. ISO Container Manufacturing and Leasing: CIMC container manufacturing plant in Xinhui, Guangdong Province.
Xinhui Yufeng X147. Ship Recycling, Hong Kong Convention, and Recycling Yards: A historic Chinese recycling yard reference in Guangdong Province (now largely inactive for international tonnage).
Xinjiang Silk Route Maritime Link F1. Maritime History: Tang-era integration of overland and Indian Ocean trade.
Xiphias Frigate F1. Maritime History: Generic Greek antiquarian rigged-vessel name.
Xiphias gladius X10. Marine Biology, Fisheries and Oceanography: Swordfish.
Xixia Inland Boat Tradition F3. Seafaring Life, Education, Professions and Institutions: Chinese inland boat training heritage.
XL Body X9. Cargo Securing, Lashing and Stability Vocabulary: Vehicle body certified to EN 12642 XL for enhanced sidewall strength.
XL Bulker X17. Chartering, Shipbroking and Freight Trading: Informal label for over-Capesize bulkers such as Valemax of about 400,000 dwt.
XL Catlin X114. Maritime Arbitration and Shipping Law Firms: Marine insurer instructing external counsel; rebranded AXA XL after 2018 acquisition.
XL Catlin Marine X145. P&I Clubs, War Risk Insurers, and Marine Insurance Markets: Marine business unit absorbed into AXA XL.
XL Lashing X104. Project Cargo Forwarders and Heavy Transport: Heavy duty lashing arrangement using oversize chains, wires, and turnbuckles.
XL Monopile X123. Offshore Wind Installation Vessels and Operators: Monopile foundation diameter 8 to 10 m, used at Hornsea projects and Borssele.
XL Quota Holding D4. Fisheries, aquaculture, blue economy and marine resources: Large quota share by a single operator, regulatory concern.
XL Tug X137. Harbour Tugs, Towage Operators and Tug Builders: Marketing term used by some operators for extra-large escort tugs above 90 t BP.
XLPE X42. Offshore Wind Installation and Cable Lay: Cross linked polyethylene insulation used in most modern submarine power cables for offshore wind.
XLPE (Cross-Linked Polyethylene) X37. Marine Spatial Planning, Subsea Cables and Submarine Pipelines: Solid dielectric insulation widely used on AC and increasingly HVDC submarine power cables.
XLPE Cable X67. Marine Electrical Systems and Shore Power: Cross-linked polyethylene insulated cable used in marine medium-voltage power circuits.
XLPE-HVDC Cable X37. Marine Spatial Planning, Subsea Cables and Submarine Pipelines: HVDC submarine power cable insulated with cross-linked polyethylene, now standard on projects such as NordLink and North Sea Link.
XLProjects.network (XLP) X104. Project Cargo Forwarders and Heavy Transport: US-based independent network of project freight forwarders.
XLR-C X65. ROVs, AUVs, USVs and Marine Robotics: See Forum XLR-C.
XLS-225 X65. ROVs, AUVs, USVs and Marine Robotics: See Triton XLS-225.
XLX Evo X65. ROVs, AUVs, USVs and Marine Robotics: See Forum XLX-Evo.
XLX-C X65. ROVs, AUVs, USVs and Marine Robotics: See Forum XLX-C.
Xmas Tree X14. Offshore Oil and Gas Marine Operations: Common abbreviation for Christmas tree.
XML X73. Marine Hydrography, Charting and ENC: The encoding language used by S-100 product specifications for metadata and dataset exchange.
XML External Entity (XXE) X139. Maritime Cybersecurity, OT Threats and Standards: Vulnerability class affecting port community system APIs that consume third-party XML payloads.
XML S-100 Exchange Set X148. Maritime Cybersecurity, IACS Cyber Rules, and Incidents: The data envelope for next-generation hydrographic products, with explicit signature and integrity profiles.
XO (Executive Officer) E2. Naval, defence and maritime law enforcement: Second in command of a warship.
XO Code X146. Port State Control Regimes, MoUs, and Inspection Systems: Not a PSC term as such, but PSC reports cross-reference "expert opinion" notes for complex deficiencies.
XOcean XO-450 X109. Maritime Autonomous Surface Ships and MASS Code: An Irish designed hybrid solar and diesel electric unmanned surface vessel used for hydrographic and environmental survey.
Xocoa Yachting F4. Recreational Boating, Yachting and Sport: Generic small builder example.
Xodus Group X57. Ocean Energy Beyond Wind: UK consultancy active in marine renewable, offshore hydrogen, and CCS technical assurance.
XOL X4. Marine Insurance, P&I and Claims: see Excess of Loss.
XPONENTIAL X119. Maritime Conferences, Trade Shows and Awards: Annual AUVSI unmanned systems conference with maritime autonomous vessel track since 1972.
Xpress Link X68. Maritime Satcom and Telecommunications: Branding occasionally used for hybrid Ka and L-band maritime services predating Fleet Xpress.
XR Forecast Tool X126. Marine Oil Spill Response and OPRC Regimes: NOAA experimental dispersant model.
Xray Flag F5. The Reference Layer: Glossary, Units, Signals and Information Sources: International Code of Signals letter X, meaning "Stop carrying out your intentions and watch for my signals."
XRF (X-ray fluorescence) X2. Marine Bunker Fuels, Lubricants and Bunkering Operations: Analytical technique for sulphur and metals in fuel and lubricants.
XRF Sulphur Analysis X115. Marine Bunker and Cargo Surveying: X-ray fluorescence determination of sulfur in petroleum products per ISO 8754, ISO 14596, ASTM D2622, ASTM D4294, or ASTM D7039.
XSAT (Expendable Salinity Sensor) D5. Coastal processes, sea-level, cryosphere and ocean observation science: Probe for measuring near-surface salinity.
XSI X44. Shipping Indices, FFAs and Freight Markets: Xeneta Shipping Index published by Norwegian benchmarking firm Xeneta, covering long-term and spot container freight rates across major corridors.
XSI-C X44. Shipping Indices, FFAs and Freight Markets: Subset of the Xeneta Shipping Index focused on contract container freight rates negotiated between shippers and carriers.
XSI-S X44. Shipping Indices, FFAs and Freight Markets: Spot container freight rate component of the Xeneta Shipping Index family.
XSim (eXpert Simulator) X144. Bridge Simulators, Engine Room Simulators, and Maritime Training Equipment: HR Wallingford fast-time and real-time simulator family.
Xstrata X124. Dredging Industry and Reclamation Contractors: Australian mining client for dredging at Townsville.
Xstrata terminal X15. Ports, Terminals and Stevedoring: historic export terminal name retained in trade documentation.
XSV (Expendable Sound Velocity Probe) X129. Hydrographic Offices, Survey Vessels and Marine Cartography: Single-use probe measuring sound velocity directly versus depth, used on ships of opportunity to support multibeam corrections.
XT (Christmas Tree) Installation Vessel E4. Cruise, offshore energy and auxiliary/specialised fleets: Subsea XT installation vessel.
XTE X168. Bridge Electronics: Radar, ECDIS, GMDSS, and IBS: Cross-Track Error displayed by ECDIS and autopilots indicating perpendicular distance from the planned route.
XTE / XTD X16. Nautical Science, Navigation and COLREGs: Cross-track error / distance from planned route.
XtendFresh X26. Reefer Containers and Cold Chain Logistics: Carrier Transicold controlled-atmosphere kit retrofitted to integral reefers.
Xtract X54. Naval Architecture Software and IACS Rules: DNV Sesam postprocessor for FEM result visualization in ship structural analysis.
Xtreme X125. Superyacht Industry, Builders and Brokers: Sunreef multihull power range branding.
Xtreme Sailing Series F4. Recreational Boating, Yachting and Sport: GC32 catamaran inshore series.
Xue Long X133. Polar Research Vessels and Polar Code Regimes: Chinese polar research icebreaker, rebuilt 1993, Polar Class equivalent PC6.
Xue Long 2 X133. Polar Research Vessels and Polar Code Regimes: Chinese Polar Research Institute icebreaker delivered 2019 by Jiangnan Shipyard, Polar Class PC3.