Peculiar finance

[Killer Phil]

I can have a healthy balance per month (as keep a small fleet due to maintenance) , what ships I have are in limited status to minimise the cost..  then I go to war and ships go to sea and all of a sudden my net monthly goes from say 20 million surplus to 150 million .. makes no sense to me.. 

[alanschu]

I notice when you go to war your fleet budget (as a percentage of GDP) doubles, so there is a big influx of budget when you go to war.

[Heet]

Your naval budget doubles when you go to war (not your GDP, your naval budget).

At Peace: Naval Budget = 4% of GDP. This gets modified by campaign events (for example +1% naval funds means you have a 4.04% budget)

At War: Naval Budget is doubled to 8% +/- the campaign events.

So at war you'll have a much higher budget, this will allow you to take ships off Limited duty, and put them on Sea Control or at sea to project power, which somewhat offsets the budget changes.  It's also a great time to start heavily investing in new shipbuilding and crew training (if it was less than 100% before).

Keep in mind that at war your overall economy tends to suffer, especially in long, drawn-out wars.  You'll notice your GDP growth takes a dive when at war (especially if you're losing and can't protect your transports or merchant marine).  It's typically better in a long campaign to stay at peace most of the time (with ships In Being or on Limited duty), and then go to war with the intent to win swiftly to minimize the impact on your GDP.