SeaQuest

In this Atari 2600 game you control a yellow submarine who must defend and rescue divers under the ocean. This isn't a bad game, but it can't compare to similar defend and rescue games, (such as Defender). You have to destroy waves and waves of enemy submarines and sharks. I am not sure how sharks could possibly threaten a submarine, but they do so in this game.

You could get a patch from Activision if you managed to get a high score of 50,000 points or more. The patch would declare you as a member of the "Sub Club", which was not in any way related to Subway, who I recall having the same thing.

"Every time you surface, you increase the game's level of difficulty.
So, keep your surfacing to a minimum, with one exception: when you've got five
divers aboard, and your oxygen's running low--surface to refill your oxygen
supply. You'll lose one diver, but you can easily pick up two or more to
resurface and gain a lot of extra bonus points.”

Steve Cartwright is the programmer on this title. Steve was responsible for some of the more amusing games that came out of Activision, such as the tooth decay based Plaque Attack.

This game is valued at around $3 USD. Games with boxes and manuals are worth more. If you simply must purchase and collect these Atari 2600 games then this is one of the better ones out there. Although if I were you I would just try to remember the thing fondly and leave it at that. Because you know you won't play it, and the box is dumb looking, so it won't even look good on your shelf.