Visitors to the Lydney Yacht Club Rally in the Forest of Dean are being invited to give their views on future plans for Lydney Harbour.
The Environment Agency has set up an exhibition of the proposed improvements at the event on Saturday.
Schemes include a boatyard, a new basin for moorings and a visitor centre.
"We have put in a bid for more money from the Big Lottery to complete the work we have already started," said Natasha Cuffley from the agency.
"We want visitors at the open day to tell us what they think.
"There will be a team of people from the partnership group to talk about the history of the harbour, where we stand now and plans for the future of the harbour."