To get me back in the water for a month or so until I can get the bits I need to fix my holy toob, I'm concocting a bodge up.
Here it is as it looks at the moment, perhaps difficult to see but major fabric structural failure in progress along the middle of the damaged area and out to both sides. The cone on the starboard side I think is heading the same way and the whole problem is due to the seams on the cone end flexing and chafing. Which at the risk of receiving another email titled "Without prejudice"

could attract some negative comment on the design front

but I won't go down that road again....
What I'm thinking is wallop a patch over the top of that (again) good enough to last for a month or six weeks till I can get the whole new tube ends here to try and do a proper repair job, which will involve cutting the ends off the tubes an inch or two in front of the original seam and sticking whole new ends in. Which I am not too confident about doing myself ... but not much option really!
Back to this question. I could do one of two things, clean up the area where the orange top layer has peeled off and stick a small patch on approximately following the outline of the yellow line, which would cover the area where it is actually leaking. Or put a much bigger patch on covering the area outlined by the blue line.
Pros and cons to me seem to be:
Yellow - can be tucked down behind the seam so less of a leading edge, but will the glue stick to the bare fabric now the orange stuff has gone?? May be weaker.
Blue - May be stronger, but leaves a forward facing leading edge that may pick up in the flow of water. May also leak along the seams.
Both are a bodge, but either only need to get me through to maybe early December just so I don't miss the first half of the summer. All the affected area covered by either patch will be in the bin anyway once I get on to the proper repair job, so no real problems from that side.
Any thoughts? Yellow or blue?
cheers
Stephen