Thought you'd be interested to hear my testament to the strength of the 4GF.
I lost my Standard yesterday leading to a proper long swim and initially a panicky "where the hell's my mat" moment. That panic was quickly replaced and increased by the realisation that it was getting slammed and dragged around sharp slate rocks covered in barnacles and mussels! At one point as I struggled to run through knee deep rippy nonsense in swim fins, I saw the backwash wedge it between two rocks and try its hardest to rip the mat in half!!!
I finally got there expecting a hissing, tattered, lifeless wreck...but not a mark on it!