That is where you started turning, you know, advance is the x this distance, advance was
the distance along the x axis where, the heading as just changed 90 degree and tactical
diameter was this, where it is that that another 90 degree here and this, see it is. You may
say, why not the maximum one? Normally, they are not the maximum 1 for, I do not
know what reason because, may be, it is much easier to measure the heading angle, you
know, locate this point more easily when the heading is just 90 degree, then to pin point
the location of maximum width so that they seemed to be closed by. So, this should be
less then equal to 5 l and this should be less than equal to 4 . 5 l. So, it again, it is very
important why these two parameter because, you see there is a restricted water harbor,
there you start to turn here, you know, see some restricted water there, etcetera, so,
obviously, it will tell you how much of space you have got in front, how much we have
got inside. See, the logic is very simple, it tells in this two, how much you can actually
has space front, therefore, it must be less than that, that is why there is a specification
with respect to the front distance, that is advance distance and also the tactical diameter
distance. In fact, it does not say here anything that I found out; may be the there is a
equation about the turning radius, actually it tells about this two.