Got the card and a couple of badges on first try.
On Ocean guard have a double machine gun at the bottom left and have a heavy cannon in front of it soaking up most of the damage. Upgrade the cannon with health and buy another to keep in stock. When wave ends switch between two heavy cannons so you don't have to repair it.
For the other two posts I had a sniper which can be fired off occasionally when it's reloaded and a decoy at the top. Probably better combinations but it worked without much trouble.