apple watch digital crown problem

Hello ,

I recently experienced à problem with the Digital Crown of my Apple Watch which is not responding anymore , sometimes it does respond and sometimes not and sometimes it responses without even touching it. I usually take for swimming in the sea since last year and I started to see rust marks on it and I tried the tap running warm water to clean the Digital Crown and it works normally for few minutes but after it didn’t respond again. Please someone help me if you have gone thought the same problem and solved it. By the way the crown felt like looss when turning it , but it is well fixed at the watch.