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Charge Day Terminology


  1. WHOI follows the Uniform Operations and Cost Terminology definitions of the University National Oceanographic Laboratory System (UNOLS) adopted in May 1976.
  2. Day is a calendar day from time 0001 to 2400, or any portion thereof.
  3. An Operating Day is a day when a ship is not at its home port and is available for service.
  4. Home Port is normally Woods Hole, Massachusetts.
  5. Port Day is an operating day when the ship is in an out-port (not at the home port).
  6. Voyage is the period from and including the day of departure from the home port to and including the day of return to the home port. Voyages are identified by ship name and a number. At WHOI the number is assigned consecutively from #1 starting when the Institution assumes operation of the ship. A voyage may consist of multiple legs.
  7. Leg is the period from and including the day of departure from any port to and including the day of return to any port. Legs are usually numbered by Roman Numerals. A leg may consist of sections (sub-legs). These may be determined by a significant change in the science party, a change in the Chief Scientist, or a change in the scientific mission, even though the ship may not have made berthing in a port. For example, a new section may be designated when a change is made in the scientific party while at sea via a shuttle boat. Legs may also be divided into sections when there is an emergency, or for “touch and go” port calls with no change in the scientific program. Sections of legs are designated with alpha characters.
  8. Cruise is a general term used to define the time a ship is engaged in a particular scientific program or mission.
  9. Stand Down is a period when the ship is not available for service, hence the days are not operating days. Depending on the reason, minimum crew may be assigned during a stand down or layup period.


  1. The charge unit for ship charges is the Operating Day.
  2. The number of Operating Day multiplied by the Daily Rate will determine the cost for a Leg (Cruise).
  3. The Daily Rate is the cost per Operating Day. It is determined by the total cost to operate the ship, as charged to the operating account for a calendar year, divided by the number of operating days the ship is available for service in that year. All days when the vessel is in service and away from the WHOI dock are operating days, except as noted below. All operating days are charge days.
  4. Sea Trials are an event to test the ship systems and otherwise exercise the vessel, which normally requires the vessel to get underway. This can occur as a result of a shipyard period, extensive changes in vital machinery or control systems, an extended inactive period or extensive maintenance. Sea trials may also occur because of changes in ancillary systems or addition of new equipment. The vessel is considered not available for service, hence sea trial days are not operating days.
  5. Inspections occur when federal regulatory bodies (e.g. US Coast Guard) and research vessel owner agencies (NSF and ONR) require routine and regular examination to demonstrate compliance with US regulations, Charter Party Agreements, UNOLS Safety Standards and operational readiness. Inspection periods may involve both at-sea operations and in-port exercises. The vessel is considered not available for service, so inspection days are not operating days.
  6. Transit (deadhead, deadhead transit) is a leg during which a ship is moving from one project or port to another with no scientific work scheduled. Transits are usually charged to the sponsor of the time periods immediately before and after the transit leg, and charges are made on a pro-rata basis. Transits to and from a shipyard for maintenance purposes are not operating days and are therefore not charge days. If a scientific program can be scheduled so that it ends at a shipyard or other maintenance location, then the leg will be charged because it is normal operating period.
  7. Port Days (out-port), days away from the WHOI dock in the service of science projects, including mobilization, demobilization, and change of the scientific crew or outfit are operating days, and hence are charge days. Normally the allocation of the cost of port days will be split between disembarking and embarking sponsoring funding sources. When the port days are uneven in number, the embarking party will normally bear the greater charge, except in special or extenuating circumstances.
  8. Operating days may be charged for a ship at the dock in Woods Hole if departure is delayed due to a science party requirement. An operating day will not be charged if the ship is responsible for the delay.
  9. Lost scientific station time at sea due to weather, scientific equipment failure or ship’s equipment failures are chargeable days until the ship returns to port. If the port is an out-port and the ship becomes unavailable for service due to mechanical failure for more than 24 hours, then the out-port days will not be charged. If the failure is due to ancillary systems failure (submersible or ROV or similar) then the days will be charged if the ship is ready for service.