This information is taken from:

CTD and Thermosalinograph Processing Procedures

Authors: Bob Beattie, Bernadette Heaney, Dave Vaudrey, Valentin Trifonov

Document file name: /home/dpg/ctd/doc/ctdproc_man.fm
Version: 5 February 2002

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4.4.3 Processing ToYo data
ToYo's are repeated down and upcasts recorded as a single station or group of stations. They may be used to give a time series of observations at a single location or be used in a towed-mode to provide spatial data. e.g., Ray Binns et. al. use them to investigate transmissometer anomalies in the vicinity of hydrothermal vents.
Both the downcasts and upcasts may have been recorded as `downcasts' so that all data could be displayed on the real time plot as offset profiles.
There will typically be groups of down/upcasts, each group possibly terminated with a dummy upcast, either at the end of the ToYo, or when it is necessary to print and restart the real time display. There may be several of these groups recorded as a single `station'. A ToYo may extend across several `stations', as a station can have a maximum of 12 dips.
Due to a limitiation of our processing software, we normally only produce calibrated data for one downcast for each station. ..........