1. Main armament size will remain the same. Example: 12" guns cannot be replaced with 16" guns.
2. Endurance can be lower than normal. Greek Navy only plans to have them near their coasts, not cruise the oceans.
3. Speed needs to be increased from the original 17 knots.
4. No more coal burning, all oil.
5. Keep the refit to a standard displacement of 16,000 tons (+3,000 tons over 13,000 tons).
6. Armor can be increased but not subtracted.
7. Budget will remain under $5,000,000 (assume that the refit will cost as much as a new ship).
8. Keep armament within the timeframe.
No one is willing to build the Greek Navy new battleships to replace them, so they have to make due with what they got.
