They are too young to walk and talk but tiny twins William and Ellenita Trykush can swim a length of a 25-metre pool at just nine months old.

The water babies love gliding up and down on their backs, kicking their legs to propel themselves along.

And as this delightful underwater picture shows, they even smile while they’re swimming.

Like ducks to water: William, left, and Ellenita, right, in their local pool

Splashing around: William, right, copies his sister Ellenita in the water

Their achievements are even more astonishing given that they were born by emergency caesarean six weeks early.

The twins’ extraordinary talent emerged during a family holiday to Cyprus in October when they began to swim underwater, unaided and without armbands.

‘It was astonishing. First they did five metres, then a width at seven metres, and then a length of 12 metres,’ said French-born Mrs Trykush, a former swimming coach.

‘There was hardly anyone in the adult pool, so I suggested to their teacher that we try the big pool.

‘They were loving it so much, they set off and did an entire length with me swimming underneath them on my back to make sure they were alright and to steer if they went off in the wrong direction.

‘Ellie was first – she always is – and William seemed to be copying his big sister.

Under water fun: The pair first swam five metres before progressing to the full length of the pool

Natural: The twins now visit their local pool twice a week because they enjoy splashing around so much

Encouragement: Former swimming coach Charlotte swims underneath her babies to check they are alright

Tired out: The babies take a well earned nap after their swimming exploits

‘We were so excited – all the receptionists and swimming coaches came to watch and were amazed.

‘One of the coaches has been teaching for 20 years and she said she’d never seen anything like it.

‘I think it comes naturally to them, as they are too young to actually learn the strokes.’

Mr and Mrs Trykush, who are both youth workers, married in September 2008 and discovered they were expecting in July last year.

It was only at their 12 week scan that they discovered they were having not one, but two.

Mr Trykush, 49, said: ‘When I saw the two little dots on the screen it was just amazing.

‘I sank to my knees and shouted “Yes!” as if Chelsea had won the cup.

‘Twins do run in both families, but it was still a bit of a shock.’

There were more surprises in store for the family.

While visiting her mother in Normandy, France, Mrs Trykush was rushed to hospital with a placental abruption – each twin had their own placenta but William’s had ruptured.

In the family: The confidence in the water of mother Charlotte, a former swimming coach, and father Victor, helps William, centre left, and Ellenita, centre right

They were born by emergency Caesarean on 7 February, Ellenita first at five pounds (2.24kg) and then William at four-and-half pounds (2.07kg).

William had swallowed a large amount of blood, which had to be sucked out his stomach, and was severely jaundiced.

‘It was a very traumatic birth and William nearly died,’ said Mrs Trykush. ‘They were in incubators for three weeks but I was just so relieved they were going to be OK.

‘They were so premature and small that although I’d intended to take them swimming as soon as possible, I was worried they would get too cold in the water.

‘So we waited until they’d had their inoculations and until they were big enough to regulate their temperature better.’

Now aged ten months, the twins go swimming twice a week – to their Duckling lesson with teacher Amy Stanley, and a practice session on the weekend.

Miss Stanley, 27, said: ‘They are the youngest children I’ve ever seen swim.

‘Normally children can swim at age three or four at the earliest.

‘A lot of babies can hang in the water, but Ellie and William can swim on top of the water and breathe independently.

‘It’s remarkable how they can do it, but they haven’t learnt, it just comes naturally.

‘They are so relaxed because Vic and Charly are so relaxed in the water and love swimming. It rubs off on them.’

Mr Trykush now has half an eye on the Olympics, having taken the twins to London this summer.

‘We won’t push them but it would be amazing to see them at the 2028 Games.

‘If they continue like this, who knows.’

On dry land: Father Victor hopes Ellenita, left, and William, right, compete at the Olympics in 2028