Tidal conditions which only occur on a handful of occasions most years caused tidal waves to form in the River Ouse this weekend.

The waves occur at the very lowest ebb of the highest spring tides of the year, as the tide turns in The Wash, funneling water up the Ouse as the inward flood begins.

Environmental consultant Kevin Holland watched the wave which came up the river from the bottom of his garden at Magdalen, near King's Lynn, around 5.30am on Saturday.

'I wasn't expecting it to be as good,' he said. 'It came up the river at about 5.30am, it was very spectacular.

'It was about 2ft high and it was across the whole width of the river. It was more like a rolling torrent.

'I was watching the moon going down, the sun coming up and a tidal wave coming up the river.'

Surfers have tried riding the waves over the years, with varying degrees of success.

Crowds gather on bridges and riverside vantage points when the tides turn at a more sociable hour than on Saturday.

But Mr Holland said after this weekend's spring tides, there would be very few further chances to see tidal waves on the River Ouse this year.

'April's going to get some very high spring tides, then after that we're not going to get any until the end of the year,' he said.

'Next year, we're going to get about 10 spring tides but I haven't worked out all the dates yet.'