Underwater Screen

As a reminder, you cannot jump out of slides underwater in Mega Man 4

Take advantage of the walls and slide all the way up to them. Jump and shoot the Mets as needed.

Be careful with the jumps and proceed as quickly as you can.

What About Rush Marine?

Besides the obvious talking points of Rush being slower than sliding, and switching to rush being an extra animation, Rush Marine simply does not fit through the spike gaps.

While potentially useful if you are uncomfortable jumping through spikes underwater, Rush Marine should be avoided.