Which is the more powerful ship?
Suppose one ship has more armor, another more speed.

Formulae designed to assign numerical values to fighting ships have been laboriously worked out, notably by Constructor Otto Kretschmer of the German navy; but the results cannot be accepted as anything except very able approximations.

Furthermore, if ship _A_ could whip ship _B_ under some conditions, _B_ could whip _A_ under other conditions.

An extreme illustration would be battleship _A_ engaged with submarine _B_ at close quarters; _B_ being on the surface in one case, and submerged in the other case.
_Aircraft_ .-- The influence of aircraft on naval operations is to be very great indeed, but in directions and by amounts that it would not be wise to attempt to predict.

The most obvious influence will be in distant scouting, for which the great speed of aircraft will make them peculiarly adapted, as was demonstrated in the battle near the Skagerak.