Entirely unrelated to the TV series seaQuest DSV, Seaquest is a submarine combat game in which you control a water vessel and must pick up divers at different levels of depth while avoiding fish and enemy subs. While most of the game takes place underwater, you also must resurface for air from time to time so your air meter doesn't run out.
Like Tetris, the game ends when the score reaches the maximum 999999. This run by morningpee aims to reach this score as fast as possible.
morningpee accomplishes this through manipulating diver and enemy spawn points and using a glitch to freeze an enemy sub, allowing him to collide with it until the maximum score is reached. A lot of effort was put into figuring out the game's RNG and the optimal point to use the No-Despawn glitch; for more information, see the author's comments.