I have read that the original Vosper triple screw boats (MTBs etc) all had three clockwise rotating screws, as seen from behind when going ahead.
Find that hard to believe though due to the torque effect! Whatever.
I have read that boats such as the USN PT Boats had the starboard and centre screws rotating clockwise and the port screw anti clockwise.
But careful inspection of the props of a restored PTB in the States seems to suggest that they also all rotated clockwise when going ahead! See attached pics of PT 617.
Pics show stbd, port and centre props in that order.
Personally for a model I would prefer to have one prop (port) revolving counter-clockwise to reduce the torque effect. That's what I intend to do with my PT-109😊
Hope this helps. Are we talking about a PTB refit here by any chance?😉
Cheers, Doug 😎