The Ship Scheduling Office occasionally has to answer inquiries from PIs or business officers about whether ship time that is unused in a particular year is or can be carried forward into the next year. The answer basically is "no."
The following portion of a recent letter from ONR explains their policy. NSF (Ocean Sciences) policy is essentially identical.
"When a Principal Investigator funded by the Oceans, Atmosphere and Space Science and Technology Department wants to schedule a cruise on any ship in the University-National Oceanographic Laboratory System, they must fill out a UNOLS Form 831 Ship Time Request (on the web). Once the cruise is scheduled on the requested ship, the Marine Operations Office of the university that operates the ship will submit a proposal to the Research Facilities Program. In the case of SIO the Ship Scheduling Office at SIO will submit proposals for ship time and technician time for all ONR funded cruises on the R/Vs Roger Revelle, Melville, New Horizon and Sproul.
If any Principal Investigator has not used ONR funded cruise days in any given calendar year, these days will be converted to dollars and put as carry-forward on the ship time proposal for the following calendar year to ONR."
In other words, any unused dollars carry forward in a lump to offset the overall cost of the institutional proposal for the new year, but there is no carry-forward of the unused time or of any obligation of time toward a particular PI or project. PIs cannot "bank" their unused time into the new year.
A PI with good reasons to wish to reschedule unused time into a new year (and there may well be such reasons) must first explain those reasons and obtain approval for that rescheduling from the pertinent research program manager, i.e., must essentially obtain a fresh approval of ship time from the research program. The research program then interacts with the corresponding ship operations program: Research Facilities Program in ONR; Ship Operations Program in NSF. If that is done, and if the pertinent operations program approves the rescheduling and conveys this approval to the SIO Ship Scheduling Office, then the new ship time proposal will be written to show both the carry-forward funds and the new schedule of the approved time. Otherwise only unused funds, not any scheduled obligation of time, will be carried forward.
Hopefully this clarifies a matter about which there has been some confusion. If there are any questions, please consult the Ship Schedulers at email@example.com or x42841.