oldschool hobie i14 scupper leak repair

I have a pretty strong leak of water into the bilge of my i14 that leaves it unusable within an hour. I have finally found the source, the inside of my right scupper tube must be cracked and leaking into the bilge as when i pour water into both scuppers with the caps on water instntly dissapears there. I cant see the crack as its somewhere in the middle of the tube. Has anyone successfully repaired this as with the inflatable as you cant access the inner tube? I was thinking the best bet may be to just seal off the scupper since the other side could compensate? I was debating between the best method, my ideas were either to insert a plug and add sealant around it, or to maybe use a repair patch and completely cover up the scupper?