This method wraps Sunbrella cloth around the old grommets so you don't have to do any grommeting. This catamaran is a Hobie 16.
I used a similar method to re-tramp my Hobie 18 with PVC/Polyester truck tarp.
If your tramp is totally gone, there's an easy method for that too.
Catamarans you get for cheap or free will need a new trampoline.
Trampolines get destroyed by UV from sitting out in the sun.
In case you're looking for a way to fix the kind of trampoline you bounce on, this same method would probably work fine for that.
I used Sunbrella UV-resistant cloth for the new tramp so it will last longer than the original one.
For comparison, here's how I re-tramped my Hobie 18 with PVC/Polyester truck tarp material.
Here's Damon, Audrey, and Star
on the test voyage. The new trampoline works great!
The other photos below are top views of the boat before and after re-tramping.