Shallow Sea is the first level of In Search of Dr. Riptide. It is a very small level, introducing the player to the basic environment. It is the only level to contain "pop-up" help boxes.
- This level differs slightly among game versions. In shareware v1.0 and registered v1.0, the submarine can move along the far upper right of the level. In registered v1.0, a mine is located in the trench left of the green locked door. In both shareware and registered v1.1, the upper right of the level is adjusted slightly higher (blocking movement there), and no mine is present in the trench.