The files you want are RTWGame#.bcs or Autosave.bcs (strategic layer save state) and RTWGame#.sac or Autosave.sac (tactical scenario save state) in Rule the Waves 2\Save\Game#, where # is the Arabic numeral corresponding to the save slot; you can read and edit these with a basic text editor like NotePad or NotePad++.
*.bcs:
- Changing current funds: Find the line Funds=[some number] in the [Nation0] block and change it so that the number reads whatever you want.
- Changing the budget: Three values you can modify - FleetSize (multiplier, probably not a good idea to mess around with it), BudgetModifier (multiplier, will change based on in-game events and high values can cause unrest), BaseResources (base value, is essentially a permanent change; be aware that base resources grow exponentially over the course of the game). Budget is calculated as 0.1 * [FleetSize] * [BudgetModifier] * ([BaseResources] + [Colonial Resources] * d); base and colonial resources can be looked up in the Almanac (see "Base resources" and "From possessions;" colonial resources are approximately 25 times the total point value of all non-home possessions) and d is a discount factor that the game manual implies exists and grows as the game progresses.
- Changing current victory points: VP lines.
- Changing current prestige: Prestige line in the [Nation0] block.
- Change current ship status: Ship#Status; if I recall correctly, 0 is AF, 1 is RF, 2 is MB, 3 is TP, 4 is R, 6 is FS, and 9 is a museum ship. Probably not useful unless you want to force a ship to become a museum ship.
*.sac:
- Force a ship to sink / resurrect a sunken ship: Ship#Sinking=[0 or 1] and Ship#Sunk=[0 or 1]; 1 is true (i.e. ship is sinking or has sunk), 0 is false.
- Edit current flotation / structure damage: Ship#CurrentFloatPoints, Ship#CurrentSuperstructurePoints
- Edit current rate of flooding: Ship#Flooding (rate of controllable flooding - can be reduced by damage control) and Ship#PF (rate of uncontrollable flooding - cannot be reduced by damage control)
If you have specific questions not covered by the above, you might try asking in the
Modding subforum.