Terry... What about the hose that is further back in the image. It looks like a PVC or Vinyl hose with red and blue thread.
Hi John, that short hose mostly above the waterline, maybe fifteen inches long, connects the electric toilet pump at the base to the bowl rim. The black double wall reinforced sea water intake hose, not shown, connects from the through hull to the intake side of the macerator pump sea water flush side. The hose you refer connects to the output side of the pump and delivers it to the bowl rim during the flushing cycle.