t to handle the common situation
in which the CTD is held at roughly constant depth (typically
a metre or so) to equilibrate, before it is lowered through the water column.
If <code>method</code> is <code>"B"</code>, the procedure is similar, except that the pressure
in the surface region is taken to be zero (this does not make
much sense, but it might help in some cases). Note that, prior to early 2016,
method <code>"B"</code> was called method <code>"C"</code>; the old <code>"B"</code> method was judged u