So here's where I'm at with this at the moment:

I've been told that we will be able to include a change to allow oceanic gunboats to deploy only on oceanic ports, and not in the rivers, in the upcoming 1.03 patch. One of the biggest issues with the gunboats, at least from my perspective, is that the Union can build 30 of them - which is desirable (and hence why the number is so high in the first place) if they're all on blockade duty, but obviously less so if they all get piled into the Mississippi. River ship build limits for the Union and Confederacy are about equal though the Union has a qualitative edge, so everything else equal, once the gunboats are taken out of the mix, the Confederate fleet should be able to hold its own now rather than being swamped out by superior numbers. "Piling into the Mississippi" will still be possible but only through New Orleans way, which is to some degree historical. Might be sufficient, might not, I'll let the community be the judge once the patch drops.

Combat stats relating to gunboats have not been changed in 1.03. Any change to them is something I would want to test thoroughly before committing to, which I haven't yet been able to do (the priority for 1.03 has been forts, blockade runners and marines).

I've tested a few of the things suggested in this and other threads. Some are showing more promise than others, however I would like to see feedback from 1.03 before pushing forward on anything at this stage - I'm always wary of making each individual update too great, over-correcting an issue and thereby creating a new one. So let's see how this patch goes, and I'll have some ideas ready for 1.04 in case we need them (1.04 won't be ready for a good while, so no need to rush!)

Adding demoralisation to gunboats is a great idea, but it's already in the game via Naval Weapons research. No need to double up on it.
- BNC