Thoughts are with you XCGB hope you’re recovering well from surgery and the treatment doesn’t set you back too much and you can still ride hard.
My daughter who’s going to be 4 tomorrow has had a picc line (removed), an implanted chamber (removed), a broviac (removed) and two broviacs (currently in place) so I’ve seen quite a bit of central veinous catheters. They don’t seem to be all that sensitive, but it’s best to avoid pulling on them! Daughter has fallen into a swimming pool and got hers properly soaked in the shower and it didn’t cause any issues. We were pretty worried at the time though!
Probably best not to try any bog-snorkelling for the moment.