Archaeologists hope to uncover some of King's Lynn's rich nautical history with a survey of the Ouse.

They will be spending a weekend looking for anchors, cannons and the remains of a wrecked ship amid the river mud at low tide.

Lynn was a key port in the medieval Hanse - a powerful alliance of medieval merchants trading their wares around the Baltic and North Sea.

Centuries ago, the town also boasted its own shipyards and a whaling fleet, which hunted the giant mammals in the seas off Greenland, towing them back to Lynn to be boiled up for lamp oil.

The survey, on June 28 and 29, is being run by the Lynn-based Marriott's Warehouse Trust, True's Yard and the West Norfolk Archaeological Society.

Dr Courtney Nimura, an intertidal archaeology specialist from the Museum of London, said they would be working from a database giving an idea what features were likely to be present on parts of the river bed exposed at low tide.

'We take maps down there and do a test,' she said. 'We know what features should be there. It's ground-truthing. The nice thing about intertidal archaeology is it's different every tide, every time the tide comes in, it changes the site.

'It's mostly preservation by record. We can't save everything, we just hope we can get there in time to do a drawing and take some photos.'

The weekend begins on Friday, June 27, with an evening of talks on nautical archaeology at True's Yard. Speakers include Dr Clive Bond, chair of west Norfolk Archaeological Society and local historian Dr Paul Richards. Places can be booked by calling True's Yard, on 01553 770479.

West Norfolk threw up one of the most significant intertidal finds of the 20th Century, when winter storms uncovered a Bronze Age timber circle on the Beach at Holme, near Hunstanton.

By studying Seahenge, scientists discovered early society was more advanced than had previously been believed.

Are you holding an archaeological dig this summer? E-mail chris.bishop@archant.co.uk.