My wife and I are new sailors. We took the Catt22 out on Sunday for our first sail. I noticed that as we got up to a certain speed I would hear a humming noise coming from below. I thought it might possibly be the cable connected to our swing keel. I had the keel, cable, and bolts checked when the bottom job was done in January. Everything checked out okay. Can anyone offer me some insight?I also asked earkier about the icebox in the galley. Does anyone use them? Are they worth using? How do you empty them after the ice melts?Thanks for everyones help.Robert