After joining Newport Gwent Dragons in 2011 the 29-year-old former bricklayer has been hit with a series of frustrating injury setbacks.
Waters ruptured knee ligaments in a 2012 pre-season friendly against London Irish, ensuring he only made one PRO12 appearance that campaign, and he suffered a repeat of the injury the following summer, putting paid to the season just gone.
He also had to endure wife Kirsty's diagnosis of cervical cancer two years ago - she has since received the all-clear - and Waters will never forget the Dragons' contributions.
"I've got mixed emotions about my new challenge because the Dragons have been incredible after all that has happened over the past few seasons," he told the South Wales Argus.
"The medical team have been flawless in getting me back to fitness after my injuries, which I think would've broken most players, while there were so many people at the region that supported me when my wife had her problems.
"I wouldn't have made it through if my teammates hadn't been there for me, so it's tough to say goodbye but I'm excited about what is ahead with London Welsh."
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