Picasso Neoprene Wetsuit Glue is the original and best! Use the product wetsuits are MADE with, Picasso 'Liquid Neoprene' Glue - 50g Tube. Picasso Neoprene glue is elastic to allow for neoprene's stretch.
 
Highly Elastic
Use to seal seams or glue patches.
Re-adheres tapes and knee/elbow pads.
The best glue for scuppers.