First thing you'll need to do is dry out the gap between the joining strips and the hull, it's probably best to put a heater underneath it and leave it for a while if you can, the last thing you want is any water trapped in there when you're glueing. Check that the fibre glass you're glueing on to is well keyed up, it probably is'nt which is why the strip came off, use a 60 or 80 grit sand paper and be as thorough as you possibly can. The PVC glue you have will be fine, i would recommend putting a thin film of glue over both surfaces and leaving it for 24 hrs. This will give you very good adhesion.
Of course you will need to make sure you remove all of the old glue first. I hope that this helps.