If at all possible, you may want to consider replacing your hose with hard PVC, using rubber "repair" couplings every six feet or so, to allow for flexing. I did this in my 33' Carver. I replaced 19 feet of hose with PVC at a fraction of the cost of marine sanitation hose. Simply went down to my local big box and picked up two ten foot lengths of 1 1/2" sched 40 PVC and at least 2 of every angle connector and two of the rubber couplers.
Of course, I could access pretty much the whole run, except for a small section. It may be different on your boat.
Frank