A remarkable D-Day veteran is finishing off landscaping his garden – at the age of 101.

Sub Lieutenant Roy Cooper, who served on board a Royal Navy minesweeper during the Allied invasion of Europe, first dug a 23ft by 13ft by 7ft pond in eight hour stints, laying 1,000 bricks in the process.

He then fitted it with a filtration system and built a wooden footbridge from which he can admire his koi carp.

Now, he is building a 8ft by 6ft wooden shed in the corner of the garden, and he is turning his garage into an annex.

Roy, who lives in a detached house in Marnhull, is thought to be the oldest surviving Royal Navy officer to take part in the invasion.

The former hairdresser – he still cuts his wife Mary’s hair – and evangelist preacher sells his own paintings, and he grows a range of vegetables in his garden.

He said: “I’m not in a wheelchair. I’m still very active and I don’t need glasses. God gave me a good body and I’ve taken care of it - I don’t drink, I don’t smoke. I eat sensibly and I push a wheelbarrow around the garden and dig holes. I believe if you don’t use it, you lose it.

“I had a heart attack five years ago and my leg swelled up and the doctor told me to rest but after a week I was so bored I had to get busy again.”

Roy was born in Southsea in 1917 and trained as a hairdresser before enlisting in the Royal Navy at the outset of World War Two. He worked as a nursing officer and laboratory technician in a naval hospital before taking part in the North African campaign and the invasion of Sicily in July 1943.

Roy returned to Britain in the run-up to D-Day and during the invasion he was second in command of a minesweeper which escorted American tugs as they towed sections of the Mulberry Harbour to Gold Beach.

The two massive concrete harbours, assembled at Gold and Omaha Beaches, were a vital link in the D-Day operation. They allowed the Allies to land up to 7,000 tons of vehicles and goods each day to facilitate the breakout from Normandy. Roy also swept mines along the Normandy coast before carrying out the dangerous work in the Dutch canals.

He has been invited to take part in a D-Day cruise at the beginning of June with surviving personnel.

Reflecting on his D-Day experience, he said: “I remember just being amazed at the size of it. There were so many ships in the water you couldn’t see the sea.

“Minesweeping was very dangerous work. The German mines had clocks on them so if they set it to 12 then 12 ships could go over them without being blown up but the 13th had it. It was very difficult to cope with.

“I’m amazed I survived but I think someone must have been looking out for me.

“There is still sadness that I lost so many friends in the war. The minesweeper I was on was sunk at Cherbourg six days after I left it, with only two survivors. It could easily have been me.”

Roy, who ran several car garages after the war, has been married for the past 40 years to former primary school head teacher Mary, 88.

She said: “He thinks if he ever slows down that will be the end of him. He has so much energy. I can’t keep up with him.”