Ah, I see now, a picture's worth a thousand words...... The "pipe" in your photo, attached to the muffler, is NOT black iron, it is all fiberglass and that is exactly where the failure usually occurs, I know it's where mine failed. If that is your intake hose the other end of that rubber hose is connected to the exhaust riser coming off the engine. That riser is black iron pipe.
I did this exact repair >>>>>
http://www.c34.org/wiki/images/f/f3/AquaLift_Muffler_Repair.pdf
I see in your sig that you have a Catalina 28, I do not know if they are the same as the 30.
Legal disclaimer: You are working with engine exhaust fumes and the potential for leaks leading to CO poisoning and possible death.
It worked out fine for me, second year and no leaks, but you do need to be fairly handy and not timid with fiberglass work. The most important tip is to install a blue "hump" hose to absorb some of the engine vibration which is what cases this failure in the first place. Again this is all dependent on your 28 being the same as the 30.
Good luck