Up to 300 people a day are exploring a former warship sunk off the South West coast last month.
The Scylla has settled on the seabed
Retired Royal Navy vessel HMS Scylla became Europe's first artificial diving reef when she was scuttled off Whitsand Bay in Cornwall on 27 March.
Hundreds of people dived on the 2,500-tonne Leander Class frigate over the Easter Bank Holiday, traditionally the start of the diving season.
Local dive centres said they are "over the moon" about visitor numbers.
Many centres are fully booked until September.
Plymouth-based diver John Busby, who with Nick Murns came up with the idea of sinking Scylla five years ago, said he had already visited the wreck several times.
Richard Lock, from Deep Blue Diving in Plymouth, said there were up to 20 dive boats over Scylla at the same time over the Easter weekend.
He said: "The main attraction of Scylla is that it is something new. It is still very much what people want to do."
The sunken warship had helped to give the city "a bit of a buzz", he said.
It is estimated the wreck will bring in £1m a year in diving revenue
Mr Busby and Mr Murns formed the Artificial Reef Consortium five years ago before other agencies became involved and took the project forward.
The Scylla, decommissioned in 1993, was bought by the Plymouth-based National Marine Aquarium (NMA) with £200,000 provided by the South West Regional Development Agency.
The aquarium's divers have been visiting the vessel almost every day, the NMA said, and webcams are due to beam images of the vessel back to the aquarium from the summer.
The Scylla has settled on the seabed close to the Liberty ship James Eagan Lane, torpedoed on her maiden voyage in 1944.
It has been estimated the new diving site will generate around £1m a year for the local economy.