I haven't seen it in let's say...nearly 20 years but the game was a cartridge for the Atari 800 system. It consisted of a fleet of ships, you controlled the lead one until it was destroyed and then another one would deploy from behind you. You could recharge the shields in water and I remember being pretty good at it, Berzerk and the great game (at least on the 800) of Mountain King...any help?

I think the game was by CBS Electronics.