Togboy - you're thinking of Pegasus and the follow up Strike Fleet for the Commodore 64. There was also a game called Gunboat for PC from EA that was similar and used the same engine as EA's SEAL Team. These are all fantastic games and I have them all, as I still have my Commodore 64 and floppy drive and I still have SEAL Team on my hard drive which runs fine through DOSBox.
This is a good game and is a cross between the above games and other Commodore 64 and early PC games like Destroyer and Destroyer Escort.
I love these type of games, and this is as good as any of them - the gameplay is suitable for all, and it is a' lite' simulation rather than a detailed one. I recommend it, and given that none of the above games are available here (to the best of my knowledge), this is deserving of a '5' as there is nothing like it on the site and it is good for what it is!
