This was a question that came up several years back, so I wonder if a final decision has been made about the slight error in size?
Since the board hexes are 1.25" across, the two hex long destroyers are 2.5" long, and the four hex long battleships are close to 5" long. The problem is with the light cruisers.
From a conversation i had with the First Sky Lord (many years back) it seems that there was an error in the sizing of the original models. The heavy cruiser at 3 hexes long should have been 3.75" long (though none were ever manufactured), and the light cruisers should have been slightly shorter, about 3.25", although the manufacturer made them too long, at a full 3.75".
So the issue now is what to do about the size of the light cruisers, and how that will affect those of us that still have the old game(s)?
Option 1.) Make the new light cruisers the correct size (~3.25") and the heavy cruisers at 3.75". However the original light cruisers would look too big compared to the new ships.
Option 2.) Make the new light cruisers the same size as the old ones (3.75"), and then make the new heavy cruisers slightly longer, perhaps about 3/8" longer than the existing light cruisers. the disadvantage of this option is that the heavy cruiser model would protrude slightly beyond the 3 hex base.
One factor to consider is if the old moulds are still available, or if theres any chance that they could be reaquired in the future