Three-Sixty Pacific was known for their simulations and war games on the PC in the DOS days. Though they were only around for about nine years, they produced a number of popular and highly rated games in these genres. This ad is for two of their probably lesser known games.
The first is Blue Max. Subtitled "The Aces of the Great War", this isn't the Blue Max you are probably thinking of if you owned a Commodore 64 or Atari 8-bit computer. That one was an isometric overhead shooter with a World War I theme. Though the theme is the same with this Blue Max, it is a simulator in which you get to fly various World War I era planes. Blue Max had a couple of very unique features. First, it allowed for two player split-screen play for cooperative or competitive play. Second, dogfights could optionally be played as turn-based strategy games. In this case a hexagonal map was shown but a frozen 3D view of the current action would also still be shown in a window.
The second is Das Boot. Also a simulator, Das Boot has you controlling a World War II German U-Boat. It was somewhat based on the novel of the same name. This was quite a realistic simulation of a Type VII German U-Boat in 1941 with the player having full control of engines, torpedoes and all other aspects of the submarine.
Blue Max was available for the Amiga, Atari ST and DOS based PCs. Das Boot was available for the Amiga and DOS. To play either one you'll have to have an old computer handy or be willing to delve into something like Dosbox or an Amiga emulator.
The above ad is from the January/February 1991 issue of PC Games magazine.