Quite a bit of fun. It took me three tries to win this, in part because of an issue I'll discuss in a moment.
* Keep the task force moving. The French have a fairly impressive battle fleet and capable air assets. Your battle group has NO air assets--so trying to engage them for a surface battle is a bad idea. You will probably never make it.
* Speaking of surface battles...I got a nasty surprise when I sneaked up to one of the French battle groups with a submarine and realized that my Mk 37 torpedoes are only good for attacking other submarines. I did manage to hurt a French destroyer by surfacing and hitting it a few times with my 5" gun, but it was not long before a French aircraft showed up and I had to go deep and run away.
* F-80s are, as far as I can tell, pretty useless against French interceptors. They do much better as attack aircraft.
* Which brings me to the issue I wanted to mention. The magazines at the air bases are...ummm...let's just say that whatever colonel was responsible for making sure the ammo dumps were well-stocked is probably going to be taken out and shot. Those lovely B-17s...hey, no one has ANY bombs for them! I even ferried them over to another base but...no, those are the WRONG 500-lb. bombs. Ack!
Now, I know some people just hit the "unlimited munitions" check box, but I prefer to set up munitions. My recommendations...
A) I could not find proof that Brazil purchased the Mk 14 torpedo, but if they had Gato submarines, they probably bought some, even though they would have known about the problems associated with them. Put 12 on each sub's magazines.
B) AB Fortaleza...add 200 Mk 82 bombs and 200 Zuni rockets to the munition dump. You now have the option to re-arm the F-80s as attack aircraft.
C) AB Recife...add 132 M64 500-lb. bombs and 50 M65 1000-lb. bombs. You can now use the B-17s.
I hope this helps. It's a fun scenario. This may improve it.
Interesting trivia: the S 14 Humaitá was originally the SS-262 Muskallunge. Muskies are the reason you should not dangle your toes in the water if you are visiting Wisconsin. :) I once saw one eat a blackbird...the bird had come down to the water to get a drink and the fish struck and snapped it down in one bite!