Thank you for picking up the book and supporting the game!
The key with When the Navy Walked is not so much that you have to adhere to a specific base size as the game was specifically written to avoid this. The key is that units on all sides of the game are based the same. As measurements are from base to base this ensures fair play. Also you will want to double your ranges and movement distances for this scale.
We use the base scales for Warrior for our 28mm WTNW games. If you are familiar with Ancients you might be familiar with a game put out by Osprey called Field of Glory or another one by a different company called Warrior. Either way both of these games provide close order and loose order bases that I feel fit perfectly for the scale of the game for 28mm figures. This chap
http://philbancients.blogspot.com/2010/02/field-of-glory-training-manual-basing.html does a fine job of explaining those basing standards.
You may want to check out my blog
http://armchairgeneral1.blogspot.com/ where I give some pointers on playing the game as well as give the rules for using cards for orders. If you have not already picked up the errata I highly suggest that as well as there were a few tweaks made to the rules to allow for tournament play.
If you have any questions feel free to email me directly at thearmchairgeneral@whenthenavywalked.com
Rob
www.whenthenavywalked.comarmchairgeneral1.blogspot.com
http://www.facebook.com/pages/WhenTheNavyWalked/170722696297361