Has it been painted? You can see the top surface is threadbare in some places.
In order to get pressure on the tube during the repair, I wouldn't inflate it as this will cause problems during gluing. I'd completely deflate the tube, but before you do that, thoroughly sand and degrease. More details here:
https://polymarine.com/pdfs/Polymari...-Use-Guide.pdf
Actually ambient temperatures are perfect right now for this type if repair outside. If you have a couple of bits of 2x4" timber and oversized G-clamps, then look them out.
With the tube deflated you should be able to lift the rear sponson and fold it in towards the transom. With the tube sanded an degreased, measure the area and have a patch pre-cut. Round the edges of the patch. Mask the area and apply the first glue layer, including the patch. This is the critical bit. You leave the patch and the tube material for 30 minutes until it's slightly tacky to touch. Apply second thin layer of adhesive, leave 5 minutes until it blooms (it will oxidise), then bring the two surfaces together, working the patch pressure from the middle out. You get one shot at applying the patch, so use the masking tape as a guide and be methodical. You shouldn't have any excess glue, as it needs to be thin layers, but any excess glue will be on the masking tape. Dust some talcum powder on it, get timber behind the tube and in front of it and whack on a couple of G-clamps to apply pressure evenly.
Don't even be tempted to check. Leave it 24-48 hours at least. Once you dismantle, remove the masking tape and pressure test. Hopefully job done.
Sula
