Ships on the Thames blew their horns to thank two friends who have helped keep mariners safe on the river, as they made their final broadcast before they retired.

Long-serving Vessel Traffic Services (VTS) officer Brian Arterton and supervisor Ray MacLean, both from Gravesend, have worked together as a watch at the Thames Barrier Navigation Centre for more than 12 years and both retired on the same day.

Mr Arterton, 68, joined the Port of London Authority in the early 60s as a deck boy on the tug Westbourne, carrying on a family tradition by working on the Thames.

His dad, Arthur, worked as a deck hand and later as a master on the Westbourne, while his grandad, Ernest, was a skipper on the shame boat. His son, Kelvin, also works at the PLA as a deputy VTS manager.

Mr Arterton said: “My job involved making sure the navigation of river traffic at the barrier and beyond was safe. It’s a role I’ve enjoyed very much.”

He added that his best memories working for the PLA included helping at the Queen’s Diamond Jubilee Pageant in 2012 and being part of the huge security effort for the London Olympics.

Mr MacLean, 68, was Mr Arterton’s supervisor and started at the PLA in 1998 as a duty marine officer.

He said: “I’ve made so many friends at the PLA and enjoyed the time I shared there, but it was the right time to retire. Getting up at 5am in the morning for work wasn’t as easy as it used to be and the commute wasn’t getting any easier.

“Working with Brian for so long had its challenges. We were diametrically opposed when it came to politics, but the banter was always good, and we’ll remain friends and golf partners. He’s better than me, but don’t tell him that.”

Mr Arterton said his retirement will allow him to spend more time with his family and that he hopes to go on a Mediterranean cruise with his wife, Wendy.

He said he would also spend time beating Mr MacLean at golf, who will improve his French and pursue other interests at the University of the Third Age.