The Squelch button/knob/whatever is actually a gain control for the receiver that varies the sensitivity of the receiver to signals. Weak "background" signals merely generate "noise" so decreasing the gain (stepping up the Squelch) reduces the receiver's sensitivity to such signals. When traveling in near shore waters, we tend to keep the Squelch pretty high so that we are only subjected to nearby transmissions that may be intended for us and less noise/chatter of which there is too much on 16. We also use the scan function covering 16 and 22A to hear CG transmissions that may be of concern.
"It is not so much for its beauty that the sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."