Too much cavitation, no hard water for prop

[kingoth]

My 1993 22'6" 4.3 liter alpha one generation 2 is shooting mass air into the water so I'm wondering the exhausting method for the prop to chop easily in ariated water and then goto "air lock" in hard water for speed is accomplished how? Is there a hose of sorts that connects to the front of the lower unit from somewheres in the upper ? My "hose" is disconnected, whatever it does? Which is? approximately 5/16 diameter, hollow, bendable yet hard plastic, black, some sort of 90 degree connector that clips? on with c clip. have only seen it under water as boat is moored. is this the exhaust gasses for the prop to be ariated???? Or am I totally mistaken, my dern mechanic seems to never be at his shop anymore.