Towed chain is an array of 6 synchronously operated CTD instruments, l
ocated on the towing cable with an interval 10 - 50 m. One of them is
a precision high-stability profiler ''Mark III''. Due to economic cons
iderations ordinary probes are used on other levels. Scanning with an
amplitude providing certain overlapping of levels is used for profilin
g fine stratification and obtaining high-resolution sections along the
route of the ship with speed 3 m/s.