Surely, Dave, I understand what you mean, my answer was indeed

too vague. This link to how

**MAN B&W** sees the question is much more

precise and circumstanciated. And more colored too

.

If you wish to have an idea of how much water resistance a ship encounters, you have the choice of estimating the power used, for instance through fuel consumption for a given speed and an estimation of the propulsive efficiency, that can give you a good guess of the resistance at this speed (and under the sea conditions you mentioned, including water depth etc..) as thrust times speed is power.

A fully wild -mad

- guess is that each 100 bhp of a well adapted screw propeller can deliver 1 ton thrust (or even more for tugs) on its shaft, of course only to validate your refined computations and check that you stayed in possible real world values.

From that, of course, initial (maximum, that is) acceleration is derived, as it is the ratio of the thrust to the ship mass.

Regards,

Luc