Hello Craig,
The canals (Suez, Panama and Keil) are treated like separate sea zones for movement pruposes ONLY.
Moving form the Eastern Med to the Red Sea would be 2 movement points.
Naval units can not "occupy" a canal zone though.
For example - if British Naval units had to retreat one space from the Eastern Med - they would end up in the Red Sea. That is the only exception to movement through a canal.
John