This might be a little late but I use the Coloplast Self-Cath Plus Soft. And yes, I do carry water with me. I use a small (4 oz) bottle of sterile saline solution. It (the bottle of saline) fits nicely into the bottle I pee into. Just rinse everything off after using it. It works great.

I just open the package, squirt a little saline solution in and slosh the package back-and-forth to make sure the entire length of the catheter get wet. Then I pull it out of it's package and use it. When done, I thoroughly rinse out my pee bottle. Everything easily fits into my under chair bag.

One 4 oz bottle of saline lasts about 2 to 3 weeks.