Need a little help here, new guy no knowledge.

[pfrench]

Stern drive question, I have a 23 Sceptre with twin I/O this is going to sound like a silly basic question but, the rubber hoses that run from the stern drive back to the boat, the hose on my port engine has come loose, how do you get that back on? its so tight in there I cant get the hose over the opening. Second, what is that hose? can i run the boat with it disconnected? what would happen? I appreciate any help as I said I am learning.