N-Sub
From Sega Retro
N-Sub is an arcade game released by Sega in 1980. It is similar to Nintendo's Heli Fire but currently nobody is sure which came first. It is also very similar to Deep Scan, except rather than control a boat firing at submarines, you're a submarine firing at boats (and other submarines). As it was a VIC Dual game, it was often bundled with another game in the arcade.
N-Sub is one of the few VIC Dual games to see a home console port. It was brought to the SG-1000 in 1983, though as with all SG-1000 games, it only saw a release in Japan and PAL regions.
Physical Scans
VIC Dual Version
US flyer
SG-1000 Version
EU cover
