Clam Skip Left Side
In the Mermalair Main Chamber, there is a bridge that can be lowered by the Mermalair Computer's master button. There is a gate guarding the master button, which can be opened by pressing 4 buttons spread throughout the entire level. The bridge allows the player to access the loading prompt to enter the Villain Containment System.
The loading prompt is active all the time, even when the bridge is not lowered. At the Spinning Towers of Power, Patrick is able to use the slide to build momentum and jump straight to the loading prompt.
With an active Cruise Boost, the player can navigate the Main Chamber and reach the Mermalair Computer's text box, unlocking the warp in the pause menu. This skips paying the clam and performing Main Chamber Skip. From the Mermalair Computer, the Villain Containment System's loading prompt can be reached. Main Chamber Lag Bash is an optimization to Clam Skip, both left and right side.
See Clam Skip Right Side for an alternate method.