We will discuss this little later. But there may be special occasions as Mr. Kumar is saying,
tugs in general do not require it, but there could be vessels which required to be moved both
forward and aft regularly- let me put that word regularly- that that is if fifty percent of the
time is moving forward and fifty percent of the time is moving backward, then I would
require a blade that is efficient both ways, but there will be a small compromise on maximum
efficiency either way- do you get my point?