but I'm not the only one
My hands are small, I know, but they're not yours, they are my own
Phantom Leader really was only part of a game. U-boat leader has all the promotions for every boat. The only thing they could add would be a mounted board. They may make a sequel, but I wouldn't wait if you want to get it.
...And the updated rulebook with the official optional rules added. But those can be downloaded from the DVG site and printed out.