tug boats are "busy" boats, I used to skipper full size tugs and found the experience both challenging and rewarding.
I never sail my Nangee with out two barges attached somewhere, be it ahead astern or alongside. I must get around to converting it to twin screw, at the moment it is single steerable Kort nozzle with 70mm prop, loads of power and very manoevreable even going astern.
Andy