Operation and maintenance (O&M)

Abbreviation for a combination carrier designed to carry oil, bulk cargoes or ore cargoes.

Observation is the active acquisition of information from a primary source.

Occupational exposure banding, also known as hazard banding, is a process intended to quickly and accurately assign chemicals into specific categories (bands), each corresponding to a range of exposure concentrations designed to protect worker health.

An occupational exposure limit is an upper limit on the acceptable concentration of a hazardous substance in workplace air for a particular material or class of materials.

Occupational hygiene (United States: industrial hygiene) is the anticipation, recognition, evaluation, control, and confirmation of protection from hazards at work that may result in injury, illness, or affect the well being of workers.

Occupational safety and health (OSH), also commonly referred to as occupational health and safety (OHS) is a multidisciplinary field concerned with the safety, health, and welfare of people at occupation.

The Occupational Safety and Health Administration (OSHA) is a large regulatory agency of the United States Department of Labor.

Ocean acidification is the ongoing decrease in the pH of the Earth's oceans, caused by the uptake of carbon dioxide (CO2) from the atmosphere.

Area A1: Covered by VHF coast radio stations providing digital selective calling (DSC) alerting services (typically 20 NM from the coast).

Navigation area beyond the outer limits of coastal waters where freedom of course-setting is not restricted in any direction for a distance equivalent to 30 minutes of sailing at the relevant ship speed.

Ocean floor disposal is a method of sequestering radioactive waste in ocean floor sediment where it is unlikely to be disturbed either geologically or by human activity.

Ocean heat content (OHC) is a term for the energy absorbed by the ocean, which is stored as internal energy or enthalpy.

Ocean Thermal Energy Conversion uses the ocean thermal gradient between cooler deep and warmer shallow or surface seawaters to run a heat engine and produce useful work, usually in the form of electricity.

An oceanic climate, also known as a maritime climate, and generally features mild summers (relative to their latitude) and cool but not cold winters, with a relatively narrow annual temperature range and few extremes of temperature.

The Oceanic crust is the uppermost layer of the oceanic portion of a tectonic plate.

31 August, 2006, the Natural Environment Research Council (NERC) took delivery of the newest addition to their research vessel fleet, the RRS JAMES COOK.

Oceanography is the study of the physical and biological aspects of the ocean.

Open Cycle Gas Turbines.

A fuels ability to resist compression detonation. The higher the number the more compression the fuel can withstand.