Sea water use (waterproof)

Thank you for your prompt answer. Today we use a PUR hot melt from Durant Italy. Just after gluing the result is excellent and it is harden very fast. Immediately after some months in sea water the glue is delaminating from the polyester weaving. We know that the PUR glue is ester-based. We also know from other applications that ester in water is hydrolysing. Can there be a possibility that this is happening here also?