I was looking for an indestructible (ie lycra-free) swim cap. It's fairly easy to find "endurance" blends of polyester in swimsuits that make them last 5 - 10 times longer than suits with lycra. I was hoping for the same in a swim cap. Well, this one is entirely polyester (80% non-stretchy and 20% stretchy), but it's covered in polyurethane (often used as imitation leather).
PRO
It should be indestructible and less prone to tearing than silicone or latex hats.
It's pretty cheap
There's no lycra!
CON
It doesn't feel all that great
It's waterproof (apparently that's a good thing, but it makes my head sweat)
It's pretty tight - I'm an adult with an average head size and short hair; sometimes the hat squeezes my face so much that my goggles fall off! I'm hoping it loosens up over time.
So, in summary, this product is probably what you're looking for, but it might be a little tight and it would certainly make me re-consider silicone again.
In case someone from Arena product development is reading this, why on Earth would you guys cover a perfectly good swim cap in PU??? My hair is going to get wet NO MATTER WHAT. If you had just made the swim cap equivalent of an endurance all -polyester suit, I would have been completely happy.
Oh, another note: I'm a long-time on-line purchaser and I have been really impressed with SwimOutlet's service. They initially sent me the wrong item. A single phone call put me straight through to a (human) representative, who resolved the issue with an absolute minimum of fuss.