Please explain how dry mask is better than non-dry mask, re. COVD 19 for example?

Prevent getting sick CDC

”People should not wear masks while engaged in activities that may cause the mask to become wet, like when swimming at the beach or pool. A wet mask may make it difficult to breathe. For activities like swimming, it is particularly important to maintain physical distance from others when in the water.”

Public Beaches CDC

”Advise those wearing masks to not wear them in the water, because they can be difficult to breathe through when they’re wet. This means it is particularly important to maintain social distancing in the water.”

Doesn’t say that they are less effective, just that it makes it harder to breathe.

Edit: Infection Control Today says ”A mask wet with exhaled moisture has increased resistance to airflow, is less efficient at filtering bacteria, and vents more. It’s not uncommon, though, says Dianne Rawson, RN, MA, in The Basics of Surgical Mask Selection, to see masks poorly fitted, placed below the nose, or wet with blood or body fluids.”

”A mask wet with exhaled moisture has increased resistance to airflow, is less efficient at filtering bacteria, and vents more”? How does it vent more? How is it less effcient at filtering bactreria though?

Thanks @SergeantQueen for responding.