This is not a simple building - it's a fantastic bit of technology itself

Peter Cowling, museum chairman

Trustees say they are not prepared to cut corners to open in time for the main holiday period.

Their chairman, Terry Vernon, said: "The contractors and developers have been working to a very tight schedule throughout the project.

"An examination of timetables in recent weeks has made it clear that the only way they could achieve the original opening date was to compromise on quality.

"That is something we are not prepared to accept."

Dock walkways

External walls have been completed at the complex, in Falmouth docks, but the interiors are not fitted out.

The museum chairman, Peter Cowling, said: "The problem here is that it's such a complex project.

The Queen and Prince Philip will visit in May

"This is not a simple building - it's a fantastic bit of technology itself.

"There have been one or two little snags along the way that have built up."

Waterside walkways around the museum may be opened earlier in the summer.

And viewing areas may be set up to allow people to look into the galleries and watch work in progress.

They will also be able to see some craft from the museum's national small boat collection.

'Royal yacht'

The museum is providing a new home for Bluebottle, a Dragon-class dinghy that was given to the Queen and Duke of Edinburgh as a wedding present.

It was used as a training boat at the Dartmouth Royal Naval College in Devon.

It has been restored by shipbuilder Maurice Hunkin in Fowey, Cornwall.

The Duke donated the boat to the new museum when he laid the foundation stone in 1999.