Glossary — H

20 terms starting with H.

• H2S Awareness Training
  Hydrogen-sulphide hazard awareness required for crew on tankers and OSVs handling sour cargoes.
• Hague-Visby Rules
  The amended 1924 Hague Rules governing carrier liability for cargo under bills of lading, widely incorporated into national law.
• Hamburg Rules
  The 1978 UN convention on the carriage of goods by sea, placing greater liability on carriers than the Hague-Visby Rules.
• Handysize
  Smallest of the modern bulk carrier classes: 10,000-40,000 DWT — flexible, port-restriction-tolerant.
• Harbour Tug
  Compact, high-bollard-pull tug used for berthing, unberthing, and shifting ships within a port.
• Hawse Pipe
  Tube through which the anchor chain runs from windlass to the side of the bow.
• Hawser
  A large rope or cable used for mooring or towing a vessel, typically greater than 25mm in diameter.
• Heavy Fuel Oil (HFO)
  Residual fuel oil with high viscosity and sulfur content, historically the primary bunker fuel for ocean-going vessels.
• heavy-lift vessel
  Specialised ship equipped with one or more large cranes (100–2 000 t SWL) for loading, transporting, and discharging oversized project cargo.
• Helicopter Underwater Escape Training (HUET)
  Mandatory survival training for personnel transferring offshore by helicopter; OPITO-accredited.
• HMPE Mooring Line (HMPE)
  High-Modulus Polyethylene synthetic mooring line — strength similar to steel wire at a fraction of the weight.
• Hogging
  Longitudinal hull bending where the middle is supported by a wave crest while the ends sag.
• Hopper Tank
  Sloped wing tank along the hold bottom corners on a bulker; aids cargo flow during discharge.
• Hot Lay-up
  A temporary idling of a vessel with full crew and systems maintained, enabling rapid return to service when market conditions improve.
• Hours of Rest
  Minimum 10 h rest in any 24 h and 77 h in any 7 days, as required by STCW VIII/1 and MLC 2006.
• Hull & Machinery Insurance (H&M)
  Marine insurance covering the vessel itself against perils of the sea, fire, collision, etc.
• Hull Cleaning
  Removal of fouling organisms and paint buildup from the underwater hull to restore vessel speed and fuel efficiency.
• Hull Stress Monitoring System (HSMS)
  Strain gauges + accelerometers + decision-support software to warn when hull-girder loads approach class limits.
• Hurricane
  A tropical cyclone in the Atlantic or eastern Pacific with sustained winds of 64 knots or more on the Beaufort scale.
• Hybrid Scrubber (EGCS)
  Scrubber that can switch between open- and closed-loop modes depending on local discharge regulations.